By John Shawn Prescott

For now this will be the last of the series of articles (15 in number), that we will post on our web site.

However I will of course in response to a need consider creating some more, if the questions and problems warrant it. You can reach me at john@aquarium-gardening.com

Clown, showing typical “white spots” of Oodinium infection

Anyway, I decided to entitle this contribution ‘Everyday questions etc’ as there is hardly a day passes, that I do not get an E-Mail or a phone call, referring to some of the questions that I will now give details of. I will also give my reply to these matters. I hope it will be helpful to some of you, if you happen to meet the same problem.

Question.1) My saltwater fish are infected with a parasite, they are showing spots, but I do not know if it is marine ‘Ick’ aka Cryptocaryon or Coral fish disease aka Amyloodinium?

Answer: Firstly one should be aware that the ’spots’ in marine ‘Ick’ are much larger and whiter than those for Coral Fish disease.

Furthermore, Amyloodinium, usually kills the first fish at least within a matter of hours of being observed. Further casualties can be expected in short order, if untreated. Cryptocaryon , typically takes 2-3 weeks progressively getting worse every couple of days, but seldom kills quickly.

In Coral Fish disease, the spots are small, often grey or yellow in colour, and cover the fish so that under light at the correct angle, they will resemble a sandpaper effect. Furthermore as they most usually in severe attacks, congregate also on the gills, one often will find an infected fish, gasping on the bottom of the tank (sometimes at the surface), desperately trying to get air. The parasites impede by their sheer numbers the passage through the gills of oxygen, as well as doing severe necrotic damage to the gills tissues.

For those of you who wish to read further into these two common parasites, so you may distinguish the difference, I would refer you to the previous articles in this series, in which I deal in detail with each of these two very common parasites. As each call to us is frantically directed to know, what to do, I may here give some pointers about treatment.

( Fish-Vet ) produce a product formerly called ‘No-Ick’. This product will eliminate Cryptocaryon irritans from fish, and is safe to use in a Reef Tank as it will NOT harm any Invertebrates. You can obtain this product from us, but because of the laws pertaining here and in the EEC, you will need to visit us with the fish and aand our local Veterinary surgeon, will have to concur in the diagnosis and write a prescription for this product. As already mentioned, the progression of this disease, is such that one usually has time to call the store and order the product. Of course the quicker one begins treatment, the surer the cure, and the less damage to the fish.

However in the case of Amyloodinium , the progression of the disease is so rapid, that unless one has a medication such as our ‘Revive’(also Reef safe) ready on hand, the chances of saving most of your fish is not high. Thus if you have in your tank a considerable investment in fish, it is certainly worth the investment to have a bottle handy so that if you do experience this devastating parasite, you have the odds stacked in your favour. ‘Revive’ can cure this scourge, in about one day, as it is lethal to the parasite.

Question 2). I think I have more than disease in my tank, possibly Cryptocaryon irritans , as well as Amyloodinium, and even a bacterial infection. Can I use remedies simultaneously?

Answer : I am sure we get asked this question several times each week. This is our considered reply, based on thousands of case histories.

First determine what the problem is. It is rare to have both parasites simultaneously in your aquarium. However if you are quite sure that you do, then treat first for Amyloodinium, with ‘Revive’, as the progression of this infestation is so fast, that all the fish will be dead unless treated immediately.

Do NOT use ‘No-Ick’ and ‘Revive’ at the same time. This can lead to problems of interaction under some circumstances, and we cannot determine, the subtle differences that will cause a problem in one set-up and not another. As ‘Revive’ only needs 2-3 days to totally eliminate the Coral fish disease parasite, and as Marine ‘Ick’ takes much longer to cause fatalities, you have time to pursue this course of action.

It is important with both medications NOT to use your skimmer, or any charcoal filtration during treatment, as either or both of these, will remove some of the active ingredients, and thus make them less effective.

After treating with ‘Revive’ for 3 days, turn on your skimmer, and use a good brand of activated charcoal in your filter, for about 12 hours, to remove any residual medication. Then add ‘No-Ick’ and treat as directed. Again turn of the skimmer, and remove charcoal from the filter, until the treatment is completed, and the C.irritans parasite has completely disappeared, whichever is the longer.

In the event that the ‘conflict’ of disease, is between C.irritans (by far the most common of the 2 parasites), and a bacterial infection, with signs of bloody lesions etc, on the sides or elsewhere on the fish, act as follows:- I always recommend to first treat for the parasite, and when this is completed, to remove the ‘No-Ick’ in the manner described above, then treat with ‘Revive’ for the infection.

‘Revive’ is effective against not only Amyloodinium but also is an excellent antibacterial agent for gram negative bacteria, which are the causative organisms for the majority of those bacterial infections which we find in the aquarium. It also is very effective against many gill flukes as well.

Question 3). Should I use my UV lamp during treatment, and can I continue to add various additives?

Answer: Although we have had examples from several Hobbyists, where they have used their UV lamp without problems during treatment with ‘No-Ick’ , there is in the literature some evidence, that there can be an unfavourable interaction between the rays of the lamp, and the active ingredients. Therefore we have warned against their simultaneous use. As I have already said, we know of many cases,

Freshwater fish with fine ’salt and pepper’ dust showing on the skin. Fish is infected with Oodinium pilluri s the freshwater form of Amyloodinium . The appearance is almost identical, and I do not have a good photo of a saltwater fish with the spots showing.

which have caused no problem, but it safer to err on the side of caution. I would also point out, that UV lamps will have no effect whatsoever, on killing the parasites, so I really see no reason to feel worried about turning off the lamp for a couple of weeks. The lamp should also not be used if treating with ‘Revive’ as one of the ingredients in ‘Revive’ is very light sensitive.

As for the use of additives, such as trace elements, Kalkwasser etc, there is no reason at all not to continue with these, and in both our experience, as well as the hundreds of Hobbyists that have reported to us, have we had a single case of negative interactions.

Question 4) . Do you recommend, using ‘No Ick’ periodically as a prophylactic treatment in my show aquarium, and if so how often?

Answer: Obviously prevention is better than cure. However I do not believe that once things are stable in the main show aquarium, that one should add our medication (or any other) as a preventative.

What I do advocate, is that every new purchase, of fish, or Invertebrates, or Live Rock etc, should be held in a small filtered quarantine tank for at least 2 weeks before being introduced to the main aquarium. This is the right place and time, to use the treatment, even if there are no signs of disease. If this regimen is followed then it is improbable that outbreaks of either parasite or bacteria will break out to cause you aggravation, losses and heartbreak.

Remember, when introducing new fish to an established tank, to do so in VERY subdued lighting, preferably in the evening. Do this as close to total darkness as you can manage. Leave off the lights for some 12 hours, and if practical move some rocks or other decorations, so that the existing inhabitants will pay more attention to searching out their favorite spot in the tank, and far less to the new arrivals. This greatly reduces stress, and the potential that this can cause an outbreak of disease.

It is important to be aware, that the C.irritans parasite has the capability to lie dormant for very long periods of time, below the epithelial layer (under the skin). It cannot be eliminated in this stage, by any treatment that we are aware of. However it also will seldom break out and cause a problem unless stress in the form of an intruder, as just mentioned, or adverse water chemistry causes it to feel it should seek a new host. By minimizing the chances of stress, one can protect your fish, from these infections to some degree at least.

Finally I would like to refer to the percentage of customers, who fail either with our, or other treatments. They are understandably upset when this occurs, and would like to know why.

In a large percentage of these failures we have been able to determine the likely reasons. There are still about 10-15% of such cases, where we are unable at this time to say with confidence that we know what is the reason. However for the vast majority of failures we can offer below, some guidelines as to the cause. ( failures amount to about 25% of total attempted treatments, so that 10-15% of these is only some 4-5%, of all outbreaks that we cannot explain)

Here are what we have ascertained as the major causes of ‘failed’ treatments.

• a) A wrong diagnosis has been made. As everyone will realize, Aspirin will not cure a broken leg. Thus if you do not make the correct diagnosis, and use the wrong treatment, not only will you not effect a cure, but as any chemical can cause some stress, you will often make the problem worse.
• b) Treatment has been instituted, but the protein skimmer, and/or charcoal filtration has been continued. Depending on the efficacy of the skimmer and the amount and quality of the charcoal, much of the active ingredients of the treatment will be removed, thus ensuring a negative result.
• c) Many aquarists are unsure about the amount of water in their tank, and often forget to include the water in their sump etc. Also they sometimes do not allow for the water displaced by large amounts oflive rock etc. Too little or too much medication, can have an negativeeffect. Too little will enable the parasite to continue it’s life cycle. Too much can have the effect of causing severe adverse effects in the fish. Before beginning treatment, it is most essential to calculate & then recheck the amount of water you are treating.
• d) The fish are in an advanced stage of infection, before treatment is begun. As you will all be aware, if we are ill, the quicker we get to a professional, and begin the correct treatment, the better our chances of a complete recovery. When one leaves the treatment too late, then it is very hard to bring back fish, that are already at death’s door.

These reasons account for by far the majority of failures in treatment. Pay careful attention to them, as well as the points above, and your success, as well as your level of expertise will move into a high percentile. The satisfaction, not to mention the good feeling of saving your fish, and thus not losing money, will add enormously to your self confidence, and no doubt many fellow Hobbyists will seek you out to advise them also.

Some concluding remarks. Each week I receive many of E Mails, and even some phone calls, requesting advice or help related to problems that the Aquarist or their child is experiencing. The vast majority of these I respond to, as many of you can testify to. However I would like anyone who is requesting such advice to take into account the following ground rules.

Like most people on this earth, I have to make a living, which I and my colleagues do, as professional consultants working with fish, as well as producing our software products, and other products. So would appreciate if your inquiries can be to the point to save both of us time etc.

I also find myself irritated by a small percentage of E-Mails I receive, which state a problem, often with very poor grammar, and insufficient information, and give no signature at all.

I think most reasonable persons would agree, that nobody would phone or write to a doctor ask their advice, and expect FREE advice without even the courtesy of the doctor knowing who, or where they lived.

Often by far the best solution to these problems is to go to the store where one bought the fish. I do realize that some stores do not have a good background in fish disease, but if the anonymous questioner, gave their name and address, then often we are aware of a store who could advice them properly, that was near to their home.

It is often extremely difficult to diagnose a problem with the very limited amount of information we are given, and that is why we produced the Fish-Vet software, as seeing the ’signs’ is far more informative that descriptions. Each person can describe the same symptom in different language. Yet seeing the fish, will tell an experienced person the answer in a moment. This is why taking the fish to a competent store, is usually the most certain way to obtain meaningful advice. We of course with a great deal of experience can often make sense of a well stated problem, but often we get E Mails that say, ‘my fish won’t eat, please reply immediately’, and others in similar vein. No name, sometimes, not even the kind of fish in trouble. .

Sometimes when a matter is urgent, and you do not believe that your dealer is up to the task of giving you sound advice, then if you can take a photo, and send it along with your message, remembering to indicate in then body of the message, the format of the photo, i.e. GIF, TIFF, JPEG etc.

John Shawn Prescott john@aquarium-gardening.com

by John Shawn Prescott

Some ideas on how to buy healthy fish, and a parasite that is becoming increasingly common.

This fish is suffering primarily from a bacterial infection, but such a site rapidly becomes infected with Tetrahymena when present in the water.

In this article I wish to deal with a freshwater parasite that my contacts in the aquarium hobby tell me is now seen very frequently , whereas previously it was a rare event. Furthermore this parasite is not easy to eradicate. Also as so many readers write me with problems about either new fish they have just bought, or a new tank, that has been just set up, and they have major problems of disease and more, I felt it would be a good time to address this problem.

Firstly then the parasite. This obnoxious species is called Tetrahymena pyroformis.

Tetrahymena cell, ciliates can be observed on the periphery

The parasite is a oval shaped ciliated protozoan, and looks at first examination rather similar to the Oodinium parasite. It is some 35 -85 microns in size and ahs the ability to multiply very rapidly once it gets established , often with disastrous results.

It’s favourite infective site is the skin, but it also can attack the fins. The parasite will invade tissue, especially if there is a small lesion, and its necrotic action will quickly cause both damage to the underlying tissues of the fish, and accelerate further damage and invasion by pathogenic bacteria. Mortalities if untreated will ensue for certain, and recognition and remedial procedures are vital if it is not to spread to all the fish in the tank.

Certain species of fish appear to especially prone to infection, among them are Guppies, also most of the other livebearers, such as Mollies. Platies, Swordtails etc, and also many of the Tetra family, also Dwarf Cichlids, are reported to be most susceptible.

Skin . Typically necrotic lesions and haemorrhaging will be seen on the various parts of the skin.

Eyes . Sometimes Exopthalmia (either unilateral or bilateral) aka as ‘popeye’ will be observed, though this is not always the case.

Fins . Fins are often also attacked and ‘patches’ may be observed in heavy infections with the naked eye, as they will show a contrasting darker colour.

Water quality . There would appear to be a close correlation between a poor water quality , i.e. one with a high organic load, and the onset of a ‘attack’ of this parasite.

Gills . In heavy ’systemic’ cases, ciliates may also be easily identified on the gills of the fish. This leads to difficulty in respiration and without treatment; the fish will quickly succumb and die due to lack of oxygen.

Tetrahymena sp. attached to the fins of a fish

It would appear from the literature that there are probably a few sub strains, and that some of these are more virulent than others. Furthermore it had been believed for a long time that this organism was in fact free living in the water, causing no harm to the aquarium inhabitants.

It would now appear more likely, that some of the sub species, and not necessarily the species ‘pyroformis’ indicted above, have established a predilection when possible, and whenever conditions allow to take up the parasitic mode, and this is been observed with ever increasing frequency on fishes imported from Asia, where it would now appear to be endemic.

In severe cases, infective sites of the parasite have been identified in the fish’s brain, kidney and muscles.

It should be noted that the organism can also live freely and survives readily on decaying organic matter , which can be in many cases, uneaten food also detrital matter. This then at some point seems to ‘trigger’ the movement of the parasite to invade suitable fish, and then the cycle of of reproduction and pathogenic effect, can quickly become explosive and lethal.

It is vital in the first instance to ensure that the water quality is of the highest standard possible, and that ALL uneaten food and any waste matter is removed, both by filters, and if need be as well by physical removal.

Indications are that the following compound can be used with some success.

1 Litre of 37-40% Formalin ( formaldehyde) 3.7 grams Methylene blue. 3.7 grams Malachite green (zinc free ONLY)

Use about 20 drops of this mixture for every 100 Litres of Aquarium water. Dose every second day and changes of water should be made about every second day and the appropriate amount of extra mixture added to compensate.

However this treatment has several important cautions.

1) Most scaleless fish e.g. Elephant noses, Clown loach and many such, plus a great many species of the Tetra family, are highly susceptible to the toxic effects of Malachite green. This can very often be fatal to them.

2) The water chemistry plays a very important role in the toxicity ( to the parasite and the fish itself) of this drug. The softer and more acid the water the more toxic the drug becomes.

Short 10 minute formalin baths in a separate treatment vessel, giving 1-2 drops of formalin per litre of water of the treatment vessel, for between 30-45 minutes, can sometimes make a great improvement. It is VITAL that the water in the treatment vessel be the same chemical and temperature as the main aquarium to avoid shock, stress etc. Watch the fish during the full treatment time, as some fish ( again scaleless especially) can be very negatively reactive to this treatment.

We have had some excellent success using the product ECO F/W, in the aquarium itself and it has no adverse effects on any species we have so far used it on. these include all of the above mentioned species. However using this treatment, firstly pay close attention to what I have already said about water quality, and secondly because the treatment is milder, it is essential to treat for the full 2 week period as indicated, even if things appear to be alright as we have often observed after about 4-5 days. This is to ensure that the parasite is totally eliminated and not just lying dormant.

As this parasite is now playing havoc all over the country, I would be most grateful to receive case histories from hobbyists and dealers, who have experienced Tetrahymena sp . and hear their experiences and treatment results, to compare with our own.

Now to the more general topic of how to avoid ‘importing’ disaster to your aquarium. Many hobbyists I hear from seem to have little faith in the advice of their dealer. This begs the question why if this be so, do they continue to buy from them. Sometimes geography will be the reason, but certainly this cannot always the answer.

Impetuosity is without doubt a major reason, as is the fact that we expect instant perfection with little input on our side.

The first thing to observe when selecting a dealer, is to find out how long they have been in business. This may be a little unfair to new entrants to the industry, but usually a store that has survived the first 3 years or more will make it, whilst failures, as in most kinds of business, will take place within the first 1-2 years. It would appear self evident, that those that make it, are usually more knowledgeable than those that do not. Also in many cases more ethical.

Secondly , does the store or/and its employees appear to have a good background in the science of fish keeping, or do you get the impression that they are trying to sell you some equipment or fish just to make a sale,.

Thirdly , do they take the time and trouble, to find out what kind of equipment you already use, and which species of fish you currently have in your set-up. This is important, because I find often, that hobbyists, have purchased incompatible fish, which then cause stress to each other, and subsequent disease outbreaks.

Fourthly , Does the store have some really magnificent show tanks, not only a reef tank, but also a planted fresh water aquarium, and in fact at least on example of how an aquarium should be , of the type YOU are interested in. It is notable to me, that in Japan, and many parts of Europe many stores appear to have as many ‘demonstration’ not for sale tanks as they do, tanks from which they do sell. This does two important things for you the buyer. It enables you to have an idea of just how beautiful an aquarium can be, when maintained properly. It shows you that the store must know what they are talking about in how to keep such a beautiful show tank.

Fifthly , Are the tanks in the store clean, the water sparkling clear, and is there, as there should be a TOTAL lack of any dead or sick fish in the tanks. NEVER buy from a store where such evident examples of problems can be seen. Every store will have some sick fish, but the good stores, will firstly quarantine all new arrivals and treat them for a few days, and certainly will pay close attention to all and any signs of problems and remove them for treatment. Sometimes I have seen good stores that be treating a tank, and will have a paper or other screen over a tank during this period, with a sign saying ‘not for sale’ or suchlike. This store is taking it’s responsibilities seriously and is likely a serious store.

Sixthly Is the fish or fishes you intend to buy eating properly. Have you seen them rush greedily for some food. Fish that are sick, or shortly to become so, very typically are sluggish or indifferent to feeding, and this is often an excellent warning sign.

Seven . Has the fish you wish to purchase been in the store for at least a week? Most problems occur either immediately on arrival or in the subsequent few days. If a new arrival especially appeals to you, and you are worried that the store may sell it before you return, then ask to leave a small deposit, as a sign of good faith. All good store owners will be happy to do this for a regular customer, and if it should get ill , or needs further treatment, you can either wait, get your money refunded, or apply it to another purchase. In every case you will avoid almost certain problems.

Eight . Is your aquarium in perfect condition, and are the fish you wish to buy, unlikely to overload the carrying capacity of your tank. Each tank can only sustain so many fish, and if in your enthusiasm you wish to capacity beyond what the tank and it’s support system can safely allow, then catastrophe is guaranteed. The old rule of about 1 inch of fish body, per gallon of water in the tank is about right, at least in fresh water, yet I constantly see this been exceeded. Remember that in nature the fish have hundreds of times this ‘living space’ and a constant natural replacement and/or natural eco- system and filtration to back it up.

Nine . Not always possible, but highly recommended. Try and have a small quarantine tank ( 10-25 gal) which you keep with some form of active biological filtration, etc, and keep the new arrival in this tank for 3-4 days after purchase. Should the worst occur, you can treat easily and effectively, without the trauma of pulling down or destroying your main aquarium, in an attempt to catch all the inhabitants, or having to treat in the main aquarium, which at the least will use far more medication. Ensure that in the ‘hospital’ tank, there is some stones or other hiding places, as otherwise the fish may easily become stressed due to fright. Normally I would not medicate, only if something appears that requires it, as all medications have some stress factor in themselves, but on occasion cannot be avoided.

Finally , read up on the fish you are keeping and wish to keep. Many fish have some special requirement in their diets, yet to many hobbyists, buy a packet of standard food, and feed that religiously every day, so that the essential missing factor in time assumes a critical importance and the fish weakens. By finding out through reading good literature you will become aware of what the needs of your fish are, and sometimes this will apply to water chemistry, temperature etc as well. Information is readily available in this day and age, so use it, and have happier and healthier fish.

John Shawn Prescott john@aquarium-gardening.com

Hobby-Vet.

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Used world wide, it will soon be available exclusively through aquarium-gardening.com.

By John Shawn Prescott

Butterfly fish showing typical early Vibrio lesion

. In this article I wish to deal with a disease which while quite prevalent in Tropical fish, is not so well known or referred to as often as it should be, in the literature. This bacterial disease goes by the name of Vibriosis The infective organism can be one of a number of varieties of this all to prevalent organism.

Vibrio bacteria are gram negative rods, which are about 0.5 X 1.5 um and are motile. When grown on suitable media they give rise to creamy coloured shiny colonies.

Possibly the most well known form is Vibrio anguillarum , called after the eels which were probably the first species to be identified in culture as been prone to infection by the pathogen.

However many other forms of the pathogen are now recorded, among them being Vibrio haemoliticus , Vibrio alginolyticus as well as others. They typically infect many forms of Marine Tropicals, but outbreaks have been reported also in some fresh water species.

Large ulcerative lesion caused by V.anguillarum

Once this pathogen is established it is very hard indeed to eradicate from a tank, without drastic measures such as pulling down the entire tank and sterilizing everything in it. This of course is not what most Hobbyists want to hear or do, but the unpleasant fact remains it is a most persistent bacteria, and can cause heavy mortality if not brought under control.

The infection has been observed in a great variety of fishes, from Damsel species, to Marine Angels, many soldier fish, squirrel fish, as well as lots of other species.

There are few infections more certain to spread to other fish in the tank, and with such virulence. Casualties are to be anticipated, and remedial action must be instituted at a very early stage, if the pathogen is to be arrested in it’s march of destruction. Although like all diseases, as I have constantly in these articles pointed out, Vibrio will be most destructive in poor environmental conditions; this pathogen can however also break out by the introduction of a fish carrying the pathogen even when the tank is in an ideal condition. For this reason no suspect fish, no matter how attractive, should ever be purchased in the hope that it will get better.

It is possible, that the outbreaks are caused by the pathogen acting as an opportunistic organism, and entering the fish, when some small but otherwise harmless breakage in the skin or another part of the anatomy, presents a suitable chance for the bacteria to multiply. This is still not sufficiently understood, but many observations would appear to indicate this.

As very few Aquarists will discover this pathogen before the disease signs manifest themselves, it is usually the case, that the pathogen will have potentially spread to other fish in the Aquarium.

Thus one should be prepared to accept that some casualties will occur, and the success of any remedial treatment will be measured therefore by the extent to which the spread of the infection can be brought under control.

Tetracycline The dosage will vary according to the chosen method.

A) 4 day bath. Use 1 gram in 100 litres of Aquarium water.

B) 24 hour bath in a separate container. Use 100 mg per litre of container water.

Tetracycline can also be used like Chloramphenicol as an addition to the feed, with the limitation as already mentioned that so often with Vibrio infections the fish will not eat. When attempting to use Tetracycline in the feed take 750 mg tetracycline HCL and mix same with 100 gram of feed. Use this mixture for at least one week, feeding twice daily in the morning and early afternoon. The feed that the medication is added to, should be highly nutritious and appealing to the fish , and beef heart ( as prepared by the method given in Untergasser’s excellent book , see references below), will appeal to such fish as may not be already to far infected.

Oxytetracycline . Use at the same dosage as Tetracycline above.

All of the above are antibiotics, and can only be obtained with a Veterinary prescription, in Europe and the UK

Please also note , that any of these antibiotics, are prone to disturb the Nitrifying bacteria in the filter bed. A very close watch during treatment, must be kept using high quality test kits, on the values of Ammonia and Nitrite. Should either or both of these important parameters, start to show meaningful measurements, then water changes and other corrective action must be taken without any delay, otherwise a potentially lethal extra problem will be added to the one under consideration. One can change the water, but far better is to only undertake these forms of treatment in a separate tank, when the problem, should it arise, can be remedied quickly and easily, by changing the water, sufficiently and frequently enough to keep the matter under control until the treatment period is over.

Revive . A company Fish-Vet has managed to produce a product termed ‘Revive ‘. This product can be used in fresh and salt water tanks , and also in Reef tanks, as it has no adverse effects on any Invertebrates or Corals. It has proven most efficacious against Vibrio infections as well as other gram negative bacteria, though NOT against gram positive. It has the unusual characteristic, that in salt water, one must use only half the dosage, which is the reverse of what most other treatments call for. Most remedies that can be used in fresh and salt water, use more in salt water. In the case of Revive , the higher pH found in salt water, acts as a potentiator which accelerates the effect of the drug, and it is important to pay attention to the instructions, as otherwise much harm can be caused to the fish.

We have had great success with this product, and a growing number of stores and Hobbyists now testify to its usefulness, in treating this and other bacterial scourges. It not only can be used in fresh and salt water, but has no effect on the water chemistry, nor most importantly on the nitrifying bacteria.

I am often asked ( about 6 times a week at least), if Revive can be used at the same time as the No-Ick product which treats Marine White Spot (Cryptocaryon irritans) . The logic of the question is that so often the White Spot parasite causes secondary bacterial infections, which in some cases at least will be Vibrio infections and in many others will be gram negative bacteria against which Revive is also effective. To try and pre-empt for some of you, who may wish to phone and ask this question, I know of no actual reason why one should not, yet I always advise against it. The reason is that any addition to the natural water, produces a strain of some kind on the fish, and no-one can be sure of the multiplying effect that these two, or any two medications can have in attempting a cure. The best advice I can give, is that if the need for both is indicated by the signs, then to finish the treatment and eradicate the White Spot first, then filter with a good quality charcoal for 24 hours to remove any residual No-Ick , and then add the Revive .

Like so many infections of fish, it is probable that Vibrios like many other pathogens, are really part of the background flora, in which the fish exist. Yet for reasons that are poorly understood, in some cases they have been detected, and yet never cause a problem, whilst in others, they just suddenly become pathogenic and cause wholesale havoc. There is a lot of research still needed to determine the actual reasons why one or the other should prevail. It may be that there are different subdivisions of the organism, which have not yet been characterized.

It may equally be, that some environmental parameter changes adversely, or that one fish, which becomes stressed or injured, causes the latent pathogen to assume a virulent form, which then can quickly spread to other fish, trapped as they are in a small body of water, i.e our Aquarium.

One other observation:- Each week I got calls or E Mail from Hobbyists, who have a problem, and are in some cases at least, in a panic to get a suitable treatment ‘yesterday’. I find it amazing that in this day and age, when the average household has a medicine chest full of common remedies, that Hobbyists most especially those, that have so often invested in their Hobby not inconsiderable sums of money, wait until disaster strikes before buying at least some of the most likely to be needed treatments. The cost of remedies versus the typical investment in a good aquarium is marginal, and some diseases such as ‘white spot’ in both fresh and marine tanks, usually occur, at some time. As speed of suitable treatment is vital , I would strongly counsel our readers to have at home the most called for drugs, as it repays in spades as they say, by being able to start treatment at the first sign of trouble, and the potential losses that this avoids, will repay many times over the cost of the small investment.

John Shawn Prescott john@aquarium-gardening.com

Bacterial Fish Pathogens Author B and D.A. Austin

Fish Medicine Author M.Stopskopf

Handbook Fish Diseases Author D. Untergasser

By John Shawn Prescott

This article was written after attending a fish disease conference in Edinburgh Scotland, where the EAFP (European Association of Fish Pathologists, had a conference, in the grounds of Heriot-Watt University. This event held every second year, brings together many hundreds of Fish Pathologists, who all have more or less the same interest. That is to say, they all work in some way or another, on fish disease.

Many of them, though not all, work in the area, of fundamental or applied research, but also many Veterinarians as well as others, who farm fish for a living attend the myriad of lectures on every conceivable topic, connected with the health of fish. As well as 3 parallel sets of lectures which run for 4 days, there are a few hundred excellent poster displays, often produced by students who are studying for their Ph.D. and use the occasion to demonstrate to a wider audience their particular area of research.

Several lectures raised matters, which I though would be of general interest to our readers, and in addition there was a session devoted to ornamental fish, their diseases and problems. I believe this is the first scientific conference of this nature, that ornamentals were given such a thorough airing, and it a tribute to the growing importance of the aquarium industry, throughout the world, as well as perhaps to the many common problems with aquaculture that such time and effort were devoted to it.

Among the speakers, was a Dr. Markus Biffar, a veterinarian who works for the very famous company of Aquarium Glaser, in Germany, one of the largest and best run companies in Europe, that exclusively import exotic fish. Dr. Biffar, a veterinarian who works for the very famous company of Aquarium Glaser, in Germany, one of the largest and best run companies in Europe, that exclusively import exotic fish. Dr. Biffar’s job is totally related to keeping the fish in the best possible health, and it is indication of how far our industry has progressed that today leading wholesalers, as well as retail shops who are serious about their business, find it worthwhile to employ such well trained specialists to ensure they keep one step ahead of the competition, as well as minimize the losses which are unfortunately an ongoing overhead in this business.

Dr.Biffar told the well attended lecture that although the aquarium trade is growing every year, that due to the many problems of disease, the industry needs more and more help, from qualified people, if the numerous problems are to be overcome. He also made a plea, that those companies that produce the countless filters, and other hardware devices should begin to produce proper scientific studies to back up their innumerable claims. This would also apply to the many treatments advocated by some 30 or more produces of medications for the Hobby worldwide.

As this writer has often commentated, he also emphasized that lack of optimum water quality which brought about STRESS, assisted infectious organisms to get a hold and run amok, when the resistance of the fish is lowered. He pointed out, that for many of the rarer species; even today we do not exactly know their specific requirements in nature, making it even harder to replicate ideal conditions. Thus companies like the one he currently works for are making intense efforts to develop state of the art diagnostic technology, for the enormous numbers of problems which are often different from fish to fish, and in fresh water alone amount to some 2000 species.

Another interesting lecture was given by Dr. A. Adams of Stirling University , which he produced by himalong with others, including workers from Kasetart University in Thailand. (This later University is one which the writer visited in May, as part of a major consultancy trip he was doing for a large American client), and the University is responsible for almost all the work on fish disease in Thailand, including most of the work, relating to the shrimp industry, in which Thailand is by far the world’s largest producer).

In this lecture Dr. Adams, related their findings in work done on Siamese fighting fish , Betta splendens. They found that Tuberculosis which is found in some 150 + varieties of fish, is often encountered in the Bettas, and although there are several forms of this bacterium, the one they encountered closely resembled Mycobacterium marinum.

They especially were concerned about this bacteria as it can be transferred to man. They reported that skin lesions caused by this infection had frequently been found in workers who came in contact with these fish that were infected. For those of you, who are not aware, a number of cases have also occurred in the western world, and it behoves anyone who handles these or other fish, to be most careful if there is any suspicion that this infection may be prevalent. The bacteria will thrive at temperatures of 37 degrees C , and this means in states such as Florida and other hot areas, extra precautions should be taken.

To date there is no way known to rid a person of the very ugly discolourations that such infection can bring about on the skin, even though the disease itself it can be arrested by modern treatment. The people in Thailand are now working with the latest in PCR technology, as well as other screening techniques to try and ensure that infected fish are detected before they are exported. However be aware that at the present time, there is no legal or other requirement that such fish be prevented from been sent abroad, and even if such were implemented, the cost of policing such a law having regard to the hundreds of producers, would be almost impossible to control.

Those of you that may have read my other articles will recall that I wrote on this precise topic, and I did not at that time know that such a specific lecture would be given in Scotland.

There were many interesting lectures, but one point that came out in several of them, which were dealing with detection of pathogens, was that the detection of a known pathogen was not necessarily an indication that the disease it caused would break out. Many forms of screening and detection using very advanced technology, such as PCR, DNA probes, ELISA and more, is the holy grail of people working with very large numbers of fish, such as are typically found on today’s modern fish farms. It is the business of the professional to try and find out at the earliest possible moment if a disease is present and likely to break out. This way so the theory goes, one can take suitable prophylactic action.

However perhaps to the chagrin, of the investigators, despite excellent advances in detection methods, they found often, and especially in wild fish as well, that pathogens that are known to cause specific diseases, were detected beyond any question of doubt, yet no disease developed. There is little question in my mind, that in many cases this is due to the fact that STRESS was not a factor, and that the pathogen, is just one part of the background normal flora, that is present very often in nature, and causes problems only when conditions become abnormal.

Again at the risk of being repetitious I would bring this all important point to the attention of all of you who keep aquaria. If you can maintain the water conditions, as well as the environmental parameters in accordance with good management practice, then even though the odd bacteria or perhaps a parasite may be present, the natural immune responses of the fish, will fight it off, much as we do when exposed to a cold etc. The addition of medication is too often used as a cure-all when more attention to water changes, good filtration etc, could have helped much more.

At the conference there were many lectures on vaccination technology and developments, and it does seem possible that in another few years, that some of the oral techniques now being pioneered by companies such as Aquaculture Vaccines Ltd, and others, will be able to be applied to our aquarium species, easily by the many producing farms, and at an acceptable cost. This is very important as perhaps you are not aware, that the DOA’s (fish dead on arrival) after importing or a few days after same, are averaging industry wide, some 20-25% of the fish. When one multiplies this figure over the industry, the figures of losses are staggering, and you dear Hobbyist, pay for all of this. The only people who gain are the airlines, who ship dead or dying fish at the same price.

Although enormous progress has been made in detection methodology, and some progress has been made in vaccines, it was disappointing that little progress has been made in really effective new drugs. This is partly at least because any new drug, must pass an enormous amount of bureaucratic scrutiny, in both North America and the European community. Although one is sympathetic to the need to ensure that we do not end up eating fish that could harm humans, due to their treatment, it sometimes seems to be carried to extremes. Malachite green, which is a known carcinogen, but a very effective anti-parasitic agent, is totally prohibited. Yet in young fish, most prone to such diseases as ‘white spot’, it can cure them in a couple of days, and there is no residual carried forward when they are ready for the table. Yet it is prohibited totally as I said. In fact in North America for the fish farmer, there are currently only about 10 ‘approved’ products that may be used on fish without restriction, and these include things like Garlic, and Hydrogen Peroxide .

Whilst in the Hobby at this time, we enjoy a wide selection of drugs which are freely available, (in the USA) I am informed on good authority that these days are drawing to a close, and that within a year or two more, they will find ourselves subjected to the same kinds of regulations that currently prevail all over Europe, where no non approved drug, may be sold except with a Veterinarian’s prescription.

Whilst I feel we have gone too far, in allowing all and everything to be sold freely over the counter, which in the case of antibiotics, is certainly causing resistant strains of bugs to evolve, it does appear to me at least, that with good will, intelligence, and some oversight, we should be able to improve things, without making life impossible, for those of us, that have dearly prized sick fish, and yet accept that some regulation is in everyone’s interest. What I would not like to see is another small army of Government regulators, making everyone’s life a misery.

The delegates who numbered over 500 from some 40 odd countries, including many representatives from Japan, the USA, Korea, Thailand, and much more, had a most fruitful week. The writer and his associate finished up the week on the Friday, with a tour (there was a choice of four), which was a visit to the oldest whiskey distillery in Scotland. This distillery appeared to be making much more money from its tourists conducted tours and sale of countless forms of souvenirs, than it could possible make from the sale of its malt whiskey, which they produced as they informed us some 400,000 litres annually. After an excellent lunch of Scottish specialties which included smoked salmon, for which Scotland is famous, venison which is now farmed extensively, and a dessert of raspberries, which that region produces copiously, we left to visit a trout farm in the nearby area.

The trout farm produces some 300 tons annually and sells some of the produce as finished table ready fish, others are grown on to a stage and sold to farms in the south of England, where the growing season is much longer. In that part of the world (Scotland), they only really get some 5-6 months actual growth. The farm is fed by a natural strong stream, and they informed the very interested party (all fish pathologists), that they vaccinated against Red mouth disease of trout, but for the most part hardly ever saw any other form of disease.

All in all a very interesting week, with a great deal of information to be digested. I do hope that some of you, will find this discourse on what we heard and saw, in some way relevant to your fish keeping, as in fact all fish share many common factors, and disease, its prevention and cure, is certainly one of them.

John Shawn Prescott john@aquarium-gardening.com

By John Shawn Prescott

In this article we will deal with an all too common infection, which goes by various names

Most typically it is called Tail rot, or Tail and Fin rot. A typical characteristic of the disease is a rotting of the tail and very often the fins, which if unchecked will lead quickly to death of the infected fishes. This is a virulent pathogen, which can infect the vast majority of fresh water fishes, and has been found to occur in almost all parts of the world.

Formation of columns by Columnaris Bacteria, on side of Platy fish

The causative organism is a bacteria usually called today Cytophaga but previously was called Flexibacter and also Myxobacteria . The disease this family of bacteria causes is most often referred to as Columnaris , which describes the easily observed charateristic of the ‘piles’ of haystack like organisms which congregate on an infected part of the fish.

Columnaris Bacteria building columns on scale x160

Scientifically speaking there are several variants of this group of bacteria, but as they all manifest similar pathology, as well as respond for the most part, to identical remedial or prophylactic techniques, it is not necessary for the reader to concern themselves with the minutiae of determinative technology, which is of course of interest to those engaged in scientific research.

The disease is brought on in many cases by fish that have been badly handled , and often have been subjected to undue stress. Among predisposing factors often noted, is a sudden rise in temperature. And the disease most frequently appears, when water temperature is above 64 degrees F.

Black Molly showing typical external signs of Columnaris infection

There are some interesting relationships between the quality of the water, and the virulence of the disease, and by being aware of these factors, it may be possible to use such information in some cases at least, as part of the remedial process.

In waters of a total hardness of 33 ppm as CaCO₃, ( details of the breakdown chemically of this finding can be found in the quoted reference below ) the pathogen was found to be at its most virulent, whilst in distilled water with zero minerals it was determined to be non pathogenic. This would indicate some form of obligate need for certain minerals in order for the bacteria to reproduce and further re-infect fish. However hobbyists should be aware, that no fish I am aware of will survive for a long period of time in pure distilled water, so any experiments along these lines, which could be helpful, must proceed in the direction, of studying the findings of the quoted researchers, and modifying suitably the waters accordingly, where this is practical.

Decaying Gill tissue, turning black, sometimes an indication of Columnaris

When fish are infected with this pathogen, the following signs can be anticipated:

Skin

There will be necrotic lesions on the skin, which often are white/grey coloured with an edging of red. These will quickly in one to two days, transform into ulcers with have an orange/yellow colour, caused by the bacteria decaying the underlying tissue.

Gills

Similar effects very typically occur on the gills, but may for the average hobbyist be somewhat harder to observe at least in the early stages. The progression of these ulcers, causes the fish to have great trouble with its respiration, and thus can quickly lead to fatalities. If the gills are examined, excessive amounts of mucous, are to be expected.

Behaviour

The fish will become very listless and lethargic, often will hang at the surface, trying to breath there, although on occasion, the fish will rest on the bottom of the tank. Reluctance to feed is very typical and the fish will become anorexic. Respiration is often rapid, as the fish fights to overcome the damage done by the infection to its gills.

Body

In some cases, the lips of the fish, will become swollen and macerated, and a milky slime like film can be observed with the naked eye on parts of the body.

Fins

Large milky patches can be seen quite easily on the fins of the fish, and this is usually an indication that the disease has progressed to a degree that cure will become much more difficult. One typical sign is the appearance of a ’saddle’ shaped lesion usually around the area of the dorsal fin, and this occurs so often, that the name ’saddle back disease’ is often used in aquaculture to describe this infection.

Water

Temperature is often elevated beyond what is normal, or the fish have been exposed to a sudden rise in temperature. Furthermore, the quality of the water, is a vital component, in getting this disease under control. Excessive detritus and less than ideal filtration, will ensure the spread of the infection. Hard water seems to make the spread of the bacteria easier than soft.

Histo-pathology

Spread of bacteria in the blood stream are a frequent occurrence, and these are referred to as ‘bacteremias’. When this occurs often other bacteria such as Aeromonads will invade as well as the Flaxibacter species, and these ‘bacteremias’ can lead to a rapid demise of many fish.

Description of the organism

The bacteria are thin rods, ( 0.5- 1.0 microns in diameter, and some 4-10 microns long). Their most noticeable feature is a unusual ‘gliding’ motion, which is not observed in other species. In wet mounted specimens they can be seen piled up into large columns which have given one of the common names to this infection.

Culture of the organism is best done at normal room temperature , and there is a culture media available called Cytophaga media), which is used for this purpose.

Transmission of infection

Once established the infection will spread through the water column, and potentially can and will infect most fish, with which it comes into contact. Heavy losses must be anticipated unless rapid identification and treatment are instituted immediately. The infection can be expected to spread most rapidly if water conditions are less than ideal, and factors that have been observed to enhance the pathogenicity are low oxygen values, hard alkaline waters, excessive nitrite levels, and even the presence of certain trace elements such as arsenic. (see refs).

The bacteria have been observed to thrive on uneaten food, and there is little doubt that they exist without being a problem in most aquaria. When however the fish are stressed, by less than ideal conditions, or when some new fish are introduced without quarantine procedures being observed, and the water in the aquarium is not ideal, then the chances of an outbreak are greatly increased.

Discus fish with acute signs of Columnaris infection

I would stress to the reader, that this disease, can be horrific should it break out, but certainly this is one infection, that can almost totally avoided, just by following good husbandry practices in your aquarium. The avoidance of stress by the routine maintenance as detailed below, should avoid any occurrence of this infection.

Such practices should employ the following techniques.

1. Ensure that you have an adequate and suitable filter for your aquarium, and keep it serviced at all times.
2. Quarantine, for a period of about 10 days, all new fish before introducing them to the aquarium.
3. Do regular water changes of around 10-15% of the water volume weekly.
4. Ensure that no uneaten food, or detrital matter is allowed to accumulate on the gravel bed of your aquarium.
5. Do weekly water quality tests, to ensure that no build up of unwanted nitrites or other undesirable measurements occur without you having time to take suitable remedial action.

Should despite all your best efforts, the infection breaks out, and you have identified the pathogen, as meeting the criteria as shown above, then the following types of treatment can be employed, and if used in good time, should minimize losses.

Treatment

The most popular drugs used in mild cases of infection are a quaternary ammonium dip, for a short period, or a more prolonged bath in potassium permanganate solution. Some persons advocate using copper sulphate, but in this writers experience, the risk of further damage to the gills of the fish, is too great, and I do not recommend this drug for this disease.

Typical patch on back of young trout due to Columnaris i.e. “Saddle back.

I will not try here to give any dosage levels, as your dealer will probably carry many variants of treatments using the above as the active ingredient. As the concentrations will vary from manufacturer to manufacturer, it is better to follow their dosages, but do make allowances for the quality of your water, as well as how far the diseases has progressed, when this is appropriate.

In severely advanced cases, when the disease has already progressed to the point that fatalities, have either already occurred or it is evident that they happen momentarily, there is as I pointed out earlier , a high possibility that further bacterial systemic infection will take place. In such cases, only the use of powerful antibiotics have any real chance of saving the fish, and the one which is most commonly used in this condition with good effect is oxytetracycline. This however needs in all European countries a Veterinary prescription.

“Yellow/brown mouth sign typical of Columnaris infection“

I would stress here, that there are very good reasons, why the hobbyist should NOT RUSH to use antibiotics as a first tool, when faced with such an infection. Also such drugs are NOT available in your aquarium dealer, and there are many down sides to trying this antibiotic first, including the fact that this drug, as well as many others, are becoming less potent, due to resistant strains of bacteria now occurring everywhere on this planet, ans well as for an ever increasing number of drugs. Furthermore, for the use antibiotics, one should be used getting good professional advice, as the tendency of the average untrained person to quit using the such, at the first sign of a cure, leads to exactly the kind of resistant strain, as well as too often a reoccurrence of the outbreak. You may be able to get your local veterinarian to assist you in how to treat your tank, should such be necessary.

John Shawn Prescott john@aquarium-gardening.com

Refs.

Chen C.R. et al (1982). Studies on the pathogenicity of Flexibacter columnaris-1. Effect of dissolved oxygen and ammonia on the pathogenicity of Flexibacter columnaris to eel ( Anguilla japonica) . CAPD Fisheries series No. 8 Rep. Fish Dis. Res. 4: 57-61

Fijan N. (1968). The survival of Chondrococcus columnaris in waters of different quality. Bull. l’Office Inter des Epizooties 69: 1159-1166.

Hanson L.A. and Grizzle J.M. (1985). Nitrite-induced predisposition of channel catfish to to bacterial diseases. Progressive Fish Culturist 47: 98-101.

Stoskopf M.K. Fish Medicine Publ. W.B. Suanders 1993. pp 271-272.

Gratzek J.B. Aquariology. Publ. Tetra Press. 1992. Pp. 261-262

by John Shawn Prescott

This article will be a start in examining the many bacterial infections to which are Aquarium fish are prone.

Tuberculosis with raised Tumour development

Before dealing with the specifics, I would like to reiterate what I stated at the outset of this series, as it is most important for all of you, who wish to prevent or cure any of these potential hazards.

Bacteria including the non pathogenic as well as pathogenic forms are usually present in small numbers on most fish. They in normal situations seldom cause any problems, as the fish’s own quite adequate immune system is more than capable of fending off any infection which may become chronic.

However if parasitic infestations become severe, so that major necrotic damage is done, to the skin, fins, gills etc of the fish, then the opportunistic bacteria will often invade the eroded area, leading quickly to a major infection, which too often can be fatal.

This situation can arise in another way, without the presence of parasites . That is when for any number of reasons the fish become stressed. This lowers their resistance, so that latent bacteria, can then quite quickly manifest themselves, causing a problem for you the Aquarist. Such infections can in some cases, then spread to other fish, though this is not inevitable.

Tuberculosis granuloma in the Liver x 76

The reasons for stress are worth remembering. Among them are poor handling in the many steps of the way, from the farm or capture, to the Importer, then to the store, and finally to you the Hobbyist. Coupled with rough handling, often comes poor water quality. Also the placing together of incompatible species. Any or all of these, will cause trauma, stress, & a lowering of the fish’s natural immune system, with the consequent breaking out of a disease, that in other circumstances may never occur. Thus it only sensible, if you wish to minimize your risks, that you try to ensure that none of these factors will apply to your specimens. It may take a little more trouble, but your reward will be fine healthy fish, and none of the heartbreak of seeing a prized specimen, succumbing and even dying to a problem, that might with a little foresight have been prevented.

Unfortunately with all the best intentions, many of you will still encounter from time to time, such problems, and we will need therefore to have an idea of the various bacterial diseases, which we may encounter, and what signs we should use to identify them , as well as remedial techniques, to be used where such exist.

Eye destroyed by TB Granuloma

It should be noted that for the purposes of identification that bacterial diseases are divided into two broad categories. These are Gram-negative and Gram-positive. This means that prior to the specific tests that determine the particular pathogen we divide them according to a simple Gram stain. This Gram’s stain is a complex formula used today throughout the world as a first determinant to identify the major bacterial group.

When swabs containing the bacteria are stained with this formula if the tissue colonies of bacteria stain Purple or Blue, then Gram positive bacteria are present, if Pink or Red is the result then Gram negative are present.

The majority of bacteria we will meet in Aquaria, are of the Gram negative type. The importance of this to the Aquarist is that the treatment is usually different for the two forms , and obviously to have any success we must know what disease we are dealing with before selecting any treatment.

It is also a fact, that in many cases of opportunistic infections, that mixed colonies of bacteria will be found, as they in many cases, will enter the wound, created as I already stated, by a parasite the ideal place for an invasion. Thus we often will opt for a broad spectrum treatment, if we suspect that this may be the case.

A practical problem, that you as Hobbyists will encounter, is that in the first instance, it is not easy to find Veterinarians who have the specialized knowledge of fish pathogens to identify the precise infectious agent. Secondly the economic value of any given fish, for the most part, will never be worth the cost in pure economic terms the fees a Laboratory or a Veterinarian, would charge for such work. This work requires much specialized equipment, and knowledge, as well as some expensive consumables.

Furthermore assuming that you find such a qualified person, or laboratory, and are willing to pay the asked for fees, the time element may render the answer academic. Most tests will take a few days to get the absolute answers, during this time, in some instances at least your fish may have passed on to another world, or at a minimum, will be more sick, than when you began.

Thus we need to be aware to the extent that is possible of the indications of the bacterial infections that we may encounter, and take such steps as are prudent, to try in most cases to remedy the problem. You should be aware, that those labs or Veterinarians who can do such work, are typically working with large Aquaculture farms, or river boards, where there is a considerable economic value involved, often running into a million pouns or more, of fish, which can be endangered. Thus these specialists do exist, but for the most part they are far removed from the problems which the Aquarist may encounter, even though in a great many instances the disease can be the same bacterial form which they encounter in their daily work.

I now propose to select certain quite commonly encountered diseases, and give the reader the most encountered signs, so that hopefully with this information, along with the aid of their trusted local dealer, some extra good literature, or a professional advisor, they can possibly both identify and apply suitable treatments.

The first pathogen we will deal with is Mycobacteria .

This Pathogen has a couple of forms viz. Mycobacterium marinum , and Mycobacterium fortuitum .

Both of these are in fact Gram positive and they give rise to a form of piscine Tuberculosis.

Miliary lesions (abscesses)on internal organs due to Mycobacterium fortuitum in adult chinook salmon

Although this disease can in fact infect almost all fish, certain species seem more susceptible than others. Among these are Black Mollies, all Gouramis, labyrinth air breathers, Neons & other Tetras, as well as most species of the Carp family.

The observable signs are : Lethargic movements, major wasting, Loss of scales & Fin tissue, ‘Popeye’ skin ulcers often with small haemorrhages, also edema.

Open TB with necrosis ( Gourami)

Most species of fresh water as well as salt water fish are susceptible, and it is very important for the Hobbyist to be aware, that this is one of the few forms of fish disease, that is communicable to humans . This transmission, when it takes place, usually manifests itself with large melanomas on the arms of the fish-keeper. They can spread, and are very difficult if not impossible to eradicate. Any Hobbyist suspecting therefore that they may have encountered this disease, is strongly advised to were surgical type gloves, when handling any fish, to sterilize all nets & other items that may come in contact with the fish, and notwithstanding all these precautions, to ’scrub up’ after handling them. These melanomas usually take some 3-4 weeks after exposure before manifesting themselves, so it is essential that the Hobbyist be aware of the danger, and take precautions, as the writer is aware of a few cases, in which the unfortunate Hobbyist has become infected and has these disfigurements for life.

Histologically in doing a postmortem we may expect to see, a number of white to gray nodules on the liver, kidney or spleen. One often finds necrotic black tissue eating away at the internal organs.

Prognosis In severe cases it is seldom possible to make an effective treatment.

Typical nodules growth on internal organs on TB infected fish

The disease is a slowly progressive one, and can take quite a long period of time, before it becomes fatal. It does not seem to spread from one fish to another, though there are cases recorded where this would appear to have occurred.

Treatment, as recommended by Stopskopf, is a combination of doxycycline & rifampin. These will not however be available from your local store and would have to be obtained from your Veterinarian with a prescription.

Loss of caudal peduncle (”tail rot”) due to myxobacteria

To try and ensure that the problem does not spread to other fish, you must take steps to ensure that your water quality is of the highest standard. Although I am against the continuous use of UV sterilizers, in this case I would approve their use. Furthermore any obviously far gone fish should be removed from the main tank at least, or even humanely ‘put down’. Normally if such methodology is carefully adopted then the problem can be brought under control.

Most observers believe that the causative organism is ubiquitously present, so that it is very difficult to eliminate it entirely. However if effective husbandry is employed, with cleaning of the gravel, along with good filtration as well as regular water changes , coupled with a varied diet which should include some live food, and the addition of a good vitamin mix, the problem can be eliminated as a cause of mortality. This will not apply of course to any fish that have developed the infection to such an extent that they have wasted away , and in such cases as I have said it is better to put them kindly to sleep, this can be done, by placing the fish in a small container with water and adding an Alka Selzer tablet. Do not dispose of the carcass by ‘flushing’ it down the toilet, as this is a prime way to spread the disease. Place the fish in some foil and dispose of it with the solid waste of the household. Also do not feed the dying fish to larger carnivorous fish, as this an excellent way to spread the infection.

John Shawn Prescott john@aquarium-gardening.com

Refs .

Aquariology Master volume Tetra Press. Pages 255-256.

Fish Medicine Ed. Dr. M. Stopskopf pp 559-560.

These excellent shrimp are typical when all goes well

This article will depart from the usual format, and relate an interesting project about Shrimp Farming, mainly in S.E.Asia., and the problems which arise of disease which have enormous economic consequences. It was compiled when I was working some years ago, for the very well known firm Monsanto as a consultant. I believe the facts and observations I made at that time, could be of great interest to many Hobbyists.

I therefore propose I hope with your understanding, to take a slightly different approach to the subject of disease in this article, based on the above to try to show the reader how some of the things we observed on this trip, relate to the all important question of disease etc, in the Aquarium industry, which at first sight might appear to very far removed from the area of shrimp culture etc.

One of the reasons, we looked at the shrimp industry in S.E.Asia, was because it is plagued with disease problems that in Thailand account for overall some 40% losses of production (=Wipe outs), of the farmed stock. These losses are in value around $2 billion at today’s prices. In other countries, such as Malaysia, & Indonesia,

Samples from the pond are taken twice daily, to check on growth & to see if any disease is showing

which we also looked at, the percentages are even worse, though as the production is not as large a Thailand, the losses in dollars are not as substantial.

The principal culprits for these losses are viruses, the worst of which is called would you believe ‘white spot’ due to it’s characteristic marking on the shrimp in the early stages before leading to mortality, which happens very

A bowl of Post Larval shrimp at day 15

quickly once it has taken hold. Another important virus is ‘yellowhead’, the name is again descriptive , also there are other bacterial diseases, which are often encountered.

When one examines the typical ponds, in which the shrimp are reared, one is struck, by the lack of information, as to the quality of the water. Although most farms take regular readings of pH , Temperature, DO(dissolved Oxygen, & Salinity) it is rare for other measurements to be taken.

Yet the farmers inform us that they cannot get the shrimp to grow to as large a size as they would like, and after some 150 days at the outside, they must take down the ponds to sell the shrimp, as otherwise they may lose them.

Looking at the ponds one can see vast amounts of Protein floating over the waters, the colour of the ponds, also would lead one to believe that very high levels of Nitrate are there, mostly due one suspects to overfeeding which causes the inevitable processes of nitrification. Those of you who keep Reef Aquariums, will be very familiar with such problems.

Shrimp ponds are fed 5 times daily by hand as shown in this photo

Any Hobbyist who attempts to breed Discus fish or other sensitive fish also find that high levels of Nitrate are very inhibitory to fish, even more so to Invertebrates to which shrimp belong.

It is hardly surprising therefore to hear in so many places that they cannot keep the shrimp for too long, to get the extra size etc, that would bring them a great deal of extra money, (a 40 count shrimp, i.e. 40 per Kilo) which is typical after 150 days rearing from the PL (post Larvae ) stage, can bring the farmer some $9/Kg. However a 30 count shrimp, which would need another 20 or so days to grow, if they could do so, would fetch some $14-15/Kg. As the typical pond when it does not have a wipe out due to disease, can grow some 6 tonnes ( Metric) per Hectare, per crop, the difference to the farmer is a major amount of money, even after one allows for the cost of extra food electricity etc.

Now as a said at the outset of this series of articles stress is probably the most important factor in the creation of conditions that invariably lead to disease, so that in these countries where so

There are nearly 1000 Shrimp hatcheries in Thailand, and they utilize an important part of the world’s supply of Artemia eggs

much money is to be made by the production of good quality shrimp, which is to a large extent a sellers market, it is amazing to find, that so many important measurements are not been taken on a regular basis, and nor are various potential interventions, been tried to see if important improvements can be made. Many of these techniques and interventions, are well known to advanced Hobbyists here in the UK, and elsewhere.

We in the Hobby, when we have expensive Aquariums, with many valued specimens, almost invariably measure on a regular basis such parameters, as Ammonia, Nitrite, Nitrate, Phosphate, and more. We are familiar with the many options for filtration , as well as Protein skimming, UV sterilization, Ozone as a reduction and purification agent, Ammonia towers, and more. For the most part we know the principles as to why we do these things, along with the impact that lack of good water quality can have on the results we expect for our prized Fish etc.

Yet all of this is done, for most of us, as a Hobby. Admittedly in one of the world’s most advanced nations technologically. It is still amazing to me, that where you have an Industry that employ’s

so many thousands of people, makes a most important contribution to the economy of the countries involved, as well as being a most important hard currency earner , yet fundamental measurements and interventions, are not made and recorded.

I mention all of this, so that you the reader may grasp, just how important all these criteria are. When you ask both the farmers, who often were simple rice farmers before taking up shrimp farming, and also when we asked some of the more educated persons working with the farmers, the reasons why the shrimp died, or would not grow etc, very few specific answers were available.

In order to try and solve any problem, one must first have all the relevant information ( sometimes the irrelevant information also). When the considerable number of water quality parameters (some 16 or more), are observed over a large number of ponds for a couple of years, it is virtually certain, that some aspects of the water quality will correlate with the commencement of disease, or the lack of growth. Imagine what would happen to your fish etc, if you never bothered to take any readings of the water quality, nor had any filtration, protein skimming, or any way to kill of pathogens. I am sure you will agree that not too many Aquariums, would have the fine displays that are today becoming the norm throughout Europe, the USA. and many other parts of the world.

Anyway, I hope that this short dissertation will make you be even more aware, of how at a practical level the application of good water management practices can have a really important result to pay of handsomely whether this is for the home Hobbyist or for a shrimp farmer. To finally prove this point, we were with a Thai company, run by Europeans, which has got a couple of farms of it’s own. This company, by applying the kind of modern techniques that I have been mentioning, has had dramatically better results than the average Thai farmer. This fact takes the discussion away from the theoretical to the practical, as they have demonstrated (in dollar terms) that good water quality and management makes a real difference and that this is expressed in large numbers of dollars, in the end result.

I do hope therefore that this article will inspire you all to be aware, that poor water quality does make a difference, that no other factor is as likely to bring about any of the many forms of disease that can strike. Therefore take measurements, intervene to improve the water quality, keep records etc, and the chances are very good, that disease either will not strike or if it does, it can be much more easily brought under control.

At the end of this extensive trip to the shrimp farms of Asia, we finished up in Singapore, where fortuitously I was able to take a few days to visit the now world famous Aquarama show which was taking place at the time we arrived. This show is the only major trade show and exhibition that is devoted ONLY to the tropical and ornamental fish hobby.

Red Snakeskin Guppies from this strain, won first in theGuppy show at Aquarama

Since its inception in 1989, Aquarama has become a major fixture in the industry calendar , and each show has resulted in more exhibitors as well as ever growing numbers of visitors. The show is unique in that all the major shows in the USA and Europe are Pet shows, with a strong representation for Tropical fish, whereas Aquarama is a show specifically for Tropical Fish and Ornamentals including of course Goldfish, Koi, and marines.

An attractive feature of this event, is that each time a really interesting fish competition is held , for most of the interesting species of Fresh water Tropicals. As Singapore is probably the largest producer in the world of so many species, along with the back up from a world class University, the entries would make one’s mouth water. To my mind the categories for most interesting fish displayed were

This variety of Cobalt Discus at Aquarama was a real show stopper.

Guppies, also many of the Discus, also as some of the Arowana’s (now bred by several farms, even though they must all get CITES certificates) , were the most interesting.

All the major European producers were represented in force, such as Eheim, Sicce, Tropica ( plants from Denmark), Aqua Medic, and many many others. Leading American companies such as Instant Ocean, Forty Fathoms, Aquarium Pharmaceuticals, etc had booths, and of course dozens of Singaporean companies, which were principally fish exporters.

In conjunction with the event every second year, they have an excellent series of Scientific lectures by invited speakers, from Universities etc, in many parts of the world. This year was no exception, & among the most interesting lecturers was Dr. Blom form the Netherlands, as well as Dr. Peter Burgess from the UK.

The presentations were divided just as are more august forums, into areas of interest, and this year dealt with

1. The emerging Asian market.
2. Ornamental Fish Production Technology
3. Health & Welfare management.
4. Conservation & sustainable resource management.
5. Demonstration workshops.

We also had time to visit a few farms. Whilst the farms are often quite simple in their layout and methodology, their productivity is enormous, the people that run them, are exceptionally friendly and hospitable. I am posting some photos for readers to get an idea of what is involved.

As is germane to these articles, disease, is always a consideration for these breeders, even more so for the exporters, as overall it is generally agreed that about 20% of the fish that are shipped, either arrive DOA (dead on arrival) or do so within a few days after being received by the importer. This is something that the Singaporean Government, through its arm of the PPD (primary production dept), is now with some more progressive exporters, trying to do something about. They have recently instituted a set of protocols which all members joining the scheme must follow, and as is so typical is this dynamic country, the protocols are being policed, so that no ‘cowboys’ can make claims if they do not follow the scientifically worked out methods to prepare for shipment, which have been proven to reduce loses by an important amount.

One thing becomes very evident in Singapore, and in the writers view at least must play no small part in the reason why Singapore has become so predominant in Ornamental fish culture; even though today the standard of living is higher than in the USA, thus they can no longer rely upon cheap labour to succeed . Therefore the degree to which all the breeders & exporters are ready to cooperate with each other, as well as with the Government agencies, and the National University, makes enormous efficiency a necessity. This very close cooperation , as well as a top rated national airline, plus an airport that is consistently rated for the last 15 or more years, as the finest in the world, gives Singapore products, transport, varieties , and a lot more, that have enabled them to become the force in our industry, that is now world famous.

Many other countries especially Malaysia, Thailand, etc, now seek to supplant them, but it will take a long time, for them to play catch up, as the educational standards in Singapore have been rated year after year in Maths and Science, the highest in the world. This approach to whatever they do, will stand them in good stead to resist the competition that they will face in the years ahead.

Guppies are raised in concrete tanks with net lining as shown in the photo taken at a leading Guppy farm

Anyway, I do hope that this departure from my normal topic, will be of some interest, I will in the next article to revert to dealing with specific problems, which will probably begin with some of the bacterial diseases, as most of the important parasites have now had an airing, although we could continue for a couple of month’s more, with some of the less common ones.

As I get frequent inquiries for advice from readers, could you please try to keep your questions to the point as much as possible, and especially give as many signs (symptoms) as possible so that I can help you. I regret that time does not allow me to get into answering questions on Aquarium filtration as well as many other subjects, so I do hope those of you, will understand this. John Shawn Prescott. john@aquarium-gardening.com

By John Shawn Prescott

In this article as the saying goes in so much advertising “in response to several requests”, I am going to deal with the parasite Amlyodinium or Oodinium. Quite a few readers have written or phoned me about this disease, including one person from Argentina, so I feel now is the time to address this so often fatal infection.

Velvet like dust spots on skin . Oodinium pillularis

Many of you will be aware that although they are variants, there are two forms that attack our fish, one that causes the freshwater infestation ( which also has more than variant), and the other which attacks saltwater fish. I will deal with both starting with the sweet-water form.

Oodinium pillularis . This is the Latin name given to the parasite that causes the disease more popularly known as Velvet , Gold dust or Rust disease. This variant is the most often encountered, but as indicated below there are also a couple at least, of other very similar forms in freshwater which occur from time to time..

The infestation is caused by a parasitic dinoflagellate that is variable in size, as the variants differ somewhat in their measurements. . Other forms that cause very similar signs are Oodinium limneticum and Oodinium vastotor They can measure in some instances more than 100 microns. Though more typical sizes are 50-70 microns.

One of the greatest problems with this parasite in both the freshwater & the saltwater form, is that most typically the Hobbyist will observe the infestation only when he sees a fish, sometimes more than one, gasping for air, and in the last stages before death.

Usually this is when the fish is laying on its side on the bottom of the Aquarium, as it tries desperately to get air by attempting to breathe at the surface.

At this advanced stage of infection it is rare indeed to save the fish, however if prompt action is taken it is possible to save other fish, as without doubt if such remedial measures are not applied then virtually all the fish will succumb, usually within a very short space of time.

The parasite attacks the skin of the fish & inserts “roots” which can easily be seen under microscopic examination (see illustrations). Another favourite site of attack are the gills of the fish,

Oodinium pilluris in the skin mucous x 630

which so typically then cause the most observed sign, that of “panting” for breath as mentioned. These parasites eat into the cells of the epithelial layer, or the sensitive tissue of the gills, destroying them in the process, After the parasite has matured it falls off the fish much in the manner of white spot in both fresh and salt water. Then having fallen off the fish it begins several stages of mitotic division, ending up with some dozens or even more of cells which are flagellated.

In both the free swimming flagellated stage as well as the parasitic stage when attached to the fish, the organism contains a form of chlorophyll. This gives the parasite its typical gold or rust colour, which also enables it to obtain food, as do plants by the process known as photosynthesis. However when in the parasitic form almost all of its nourishment is obtained at the expense of the host, and this causes tremendous damage which leads to death, once the fish is heavily parasitized. On the fish the dinoflagellate form grows in size about 5-6 times, before falling of and replicating itself in the free swimming form.

Oodinium sp. in skin mucous x 400

These flagellated free swimming forms are in fact dinoflagellates, which must within the space of one day find another fish to infect or they will die. Their relatively short life cycle along with massive reproductive capacity ensure that if an outbreak occurs and it is left uncontrolled heavy mortalities will ensue. Thus the Hobbyist should be most careful and always be prepared to treat any sign of this obnoxious pest. Fortunately it is not too common, but has no equal in the speed in which it can cause havoc in any Aquarium unfortunate enough to have an outbreak. Sometimes a few fish will survive an outbreak for reasons that are not entirely clear, these fish often have developed an immunity of some form to the parasite.

Younger fish appear to be much more susceptible to the parasite, perhaps because they have a less well developed immune system. If young fish become exposed the casualties will almost invariably be much higher. However if untreated, even adult fish will succumb

Water .

Without any doubt less than ideal water quality is one sure way, to help in the outbreak of any parasitic infection, & in this respect Oodinium is no exception. However the primary reason for its introduction is usually to be found elsewhere in this instance.

Behaviour .

Gasping for air, with very rapid respiration, most typically on the floor of the Aquarium, but sometimes at the surface, are nearly always observed. In the early stages of an infection, “flashing” or rubbing & scratching are often indications, as the fish tries without success to rub off the irritating organisms.

Fins .

Fins can become clamped and folded.

Body .

The most observed feature of this infestation, is a salt & pepper effect of hundreds of small dots, usually with a pall or colour of gold/yellow or rust , which give the appearance that the fish has been covered with a special form of talcum powder. It is sometimes difficult to see this unless the light is coming from the back, & glances off the fish, when it can easily be seen. This advanced phase of infestation is however almost invariably fatal, & the Hobbyist should try to become aware of the earlier signs if he/she wishes to be able to take meaningful prophylactic action.

Gills

. Excessive mucous will be a sign that the parasite is attacking the gills, & a smear as often described previously should easily confirm this.

Skin .

The skin, becomes “dusted” with hundreds of small raised parasites, giving a colour which according to the variant of the form encountered will be from a yellow gold colour to an almost red shade.

Histo-Pathology .

A scraping of the skin, or gills will invariably show signs of the dinospores , which have a very easily recognized outline. Once the infestation has been confirmed remedial action should take place right away.

Prognosis .

As already stated, if the problem is only discovered when the parasite has made large inroads into many fish, then severe casualties are to be anticipated. Older fish of certain species often will resist the infection, though they will also succumb in many instances if no action is taken. Young fish typically will die like flies, if they are not helped with appropriate action by the Aquarist. However if a suitable remedial regimen is introduced, excellent results can be expected.

Several forms of treatment have given good results. Among them are:-

Heat treatment ( by raising the temperature by some 4-6 degrees C , to about 86F or 30C. ). . At the same time illumination can be employed for the full 24 hour cycle, as this can disrupt the life cycle of the parasite helping to cause it to “burn itself out”.

This often works, but in a mixed tank, however with species such as White Clouds as well as several others which will not tolerate the higher temperatures it is a risky procedure

Use of Quinine hydrochloride at 1 grm to 100 Litres of water as a continuous bath for about 3 days. Reports are variable but mostly good . When the treatment is finished which if possible should be done in a quarantine tank, the water should be either thrown away, or filtered over charcoal.

Use of Copper sulphate at 320 mg of Copper Sulphate in 1 Litre of pure water ( distilled). Use this solution to treat the tank water at 1 ml per 1 gal (US Gal) . This treatment is widely referred to in the literature, but has to be used with extreme care, as many fish are highly susceptible to Copper, and vary species by species in the toleration of it. Furthermore the hardness or otherwise of the water plays a critical role in the effect of the Copper. If it is not hard enough then no benefit will ensue. In addition as Copper tends to fall away, in the treatment of a new tank, that has not been previously exposed to Copper, the Copper level must be monitored frequently if good results are to be expected, and this is often just not practical for the average Hobbyist who has to work during the day.

The treatment of choice is an Acriflavine drug , ( Fish-Vet makes a combination drug Revive, using this in combination with other chemicals that gives excellent results). To make up your own Acriflavine you should obtain the neutral form & use it at 3mg of the Acriflavine in a stock solution of 330 ml. Then use this stock solution at 10 ml to treat a Gal or 4.5 litres. Do not use any charcoal during treatment, note that subdued lighting is recommended.

We have found over many years of experience, that whilst no drug is perfect, Acriflavine or some of its close relatives give an excellent result with minimal effect on the fish. After treatment charcoal should be used in the filter to remove any residual “green/yellow” cast to the water.

Other reported treatments include the use of Permanganate of Potash, sometimes used with rock salt, but these treatments have little back up documentation, so the reader is advised to proceed with caution in any such experiment.

This is the form of the parasite that gives rise to the disease known as Coral Fish Disease.

There are many similarities between this marine variant of the parasite and the fresh water forms.

The salt water Hobbyist should take into the account the differences and not make an error in diagnosis. I will now define some of the special features of the salt water form .

In the fresh water forms O. pillularis & O. limneticum , the organism’s primarily attack the skin, & then spread to the gills. In the saltwater form O. ocellatum the parasite seeks out the gills and may then spread to the skin.

Oodinium ocellatum

Slide shows parasite attached to the gills of a fish, this interferes in oxygen transpiration causing suffocation.

By the time the latter takes place however, the gill damage is almost invariably so severe, that the typical “first alert” I have already mentioned of seeing a fish “gasping” on the bottom of the tank, is unfortunately all too common. They damage to the gills, causing haemorrhaging, swelling, and intense necrosis, which lead to an inability of the fishes gills to pass sufficient oxygen, which leads to suffocation & death.

The reproductive phase of the free swimming dinoflagellate takes place optimally in water of a pH of 8.0- 8.2 with a density of 1.012- 1.021 and with a higher than desirable organic load, especially of Nitrate.

Water.

High organic load, with less than optimum water conditions, can often serve as the precursor for an outbreak. It thrives in Temperatures of 25-30 C , & salinity of 1.012-1.021.

Behaviour.

Gasping for air, with very rapid respiration, most typically on the floor of the Aquarium, but sometimes at the surface, are nearly always observed. In the early stages of an infection, “flashing” or rubbing & scratching are often indications as the fish tries without success to rub off the irritating organism. If the Hobbyist can pick up this “flashing” action at an early enough stage there is a chance he /she can prevent mortality

Gills .

Excessive mucous will be a sign that the parasite is attacking the gills, & a smear as often described previously should easily confirm this. Heavy necrotic damage is easily observed even with a good hand magnifier.

Skin .

The skin will show “gray” patches which if examined closely will manifest a “dust like” appearance, giving the skin a “velvet” look, which has given rise to an alternative name for the disease. Some haemorrhaging may also become evident.

Histo-Pathology

A scraping of the skin, or gills will invariably show signs of the dinospores , which have a very easily recognized outline. Once the infestation has been confirmed remedial action should take place right away.

Prognosis.

The disease as with its freshwater counterpart, usually springs itself upon the awareness of the Hobbyist, with the first fish or more, giving their last gasps as said on the bottom of the tank. At this stage seldom can such fish be saved, so the outlook for them is very poor. If however there are still large numbers of uninfected fish, or some only lightly infested, then if prompt & suitable action is taken, it should be possible to save the others.

The remedy for the saltwater form is rather difficult. Copper has often been indicated as a drug of choice, but has many problems in its use, as well as been dangerous to the fish in even small overdoses, especially if even minor damage has already occurred to the gills of the fish. In Reef tanks it cannot even be considered.

Methylene blue , has been used with some success, as it has the advantage of been an excellent oxygen transporter, which aids the transpiration of oxygen to the fishes gills. Methylene blue however is highly toxic to Nitrifying bacteria, & its use, should be confined to a separate quarantine tank only. If used a 1% stock solution should be made (1 grm in 1 Litre of pure water). Use 1ml of this stock solution for each 4.5 litres of water to be treated.

Acriflavine & related compounds have proven very effective, & this as in salt water has given the writer & his co-workers the best consistent results over the years. (Fish-Vet makes a product called Revive based on this experience, which has an excellent track record.) This product can be used in a fish only and /or a reef tank, and will not impact adversely the Corals etc. Carbon & Protein skimmers should not be used during the treatment period, as they pull out of the water, much of the useful active ingredients, but may be used to clear the tank once treatment is completed. Lighting should be subdued during the treatment period.

In both the fresh-water & saltwater form of the disease, the reproduction and hence the eventual intensity of the infestation is closely related to the temperature. Lower temperatures will slow down the reproduction of the parasite, and thus possibly give the Hobbyist a little more time to take effective remedial action. The Hobbyist must evaluate however the species he/she has in their tank, and the tolerance for a lower temperature that their collection of fish, is likely to withstand.

Some freshwater species such as white clouds will thrive in lower temperatures, others such as Discus, will emphatically not.

The reverse use of temperature may also be employed, by increasing the Temperature by quite a number of degrees as indicated above. This has the effect of speeding up the parasite’s life cycle, combined with the use of a suitable treatment as well as employing a prolonged photoperiod, often causes the parasite to burn itself out. If such a technique is employed then the lowered oxygen level of the water must be compensated for, by increasing the aeration substantially.

Authors note to readers: -

I am very gratified, by the increasing numbers of inquiries coming from readers of these articles. I will continue to answer queries that are sent to my E Mail address (john@aquarium-gardening.com). However as like all of us, I have other work to do, to earn a living, it would help if you could make your inquiries as specific as possible, as sometimes I have to read through a great amount of non relevant material before I am able to discern the question.

John Shawn Prescott john@aquarium-gardening.com

Refs .

Diseases of Fish C.van Duijn Jr. P 52-56. Iliffe Books UK

Handbook of Fish diseases Ed. Dieter Untergasser p. 89-90 TFH Publications.

Papperna I. (1980) Amyloodinium ocellatum (Brown 1931) (Dinoflagellida) infestations in cultured marine fishes in Eilat , Red Sea: epizootiology and pathology J.Fish Dis 3: 363-372

Noga E. (1987) Propagation in cell culture of the dinoflagellate Amyloodinium , an ectoparasite of marine fishes Science 236. 1302-1305.

Cheung P.J., Ruggieri G.D., and Nigrelli R.F. (1978) Effects of temperature & salinity on the developmental cycle of Oodinium ocellatum Brown (Mastigophore: Phytomastogophoresa: Dinoflagellida)(abstract) The Fourth International Congress of Parasitology in Poland.

Negrelli R.F. (1936) The morphology, cytology, and life-history of Oodinium ocellatum, a dinoflagellate parasite on marine fishes. Zool N.Y. 21: 129-164.

John Shawn Prescott

In this article I propose to deal with a very common fresh water parasite viz. Gyrodactylus & a Marine parasite called Brookynella.

Gyrodactylus elegans. Photo shows embryo developing inside the parasite.

Gyrodactylus causes a condition which is termed Gyrodactylidiasis, and this is the name given to the adverse effects that this group of parasites causes to fish when an outbreak occurs.

This very broad group of parasites is widely distributed, & attacks many species of tropical fish kept in Aquaria

Saltwater form of the parasite showing typical hooks which are common to all forms of this species. Photo by courtesy of Dr. Mo. of Central Veterinary Laboratory Oslo Norway.

For some reason Labyrinth fish do not appear to be often affected, some authors claim that darker coloured fish, are attacked less frequently, though this latter is not the writers experience.

The popular name of this family is called “Flukes” and in fact they are skin or gill flukes, which attach themselves to the skin or gills of the fish, and thereby can cause a great deal of damage.

As with almost all the common infestations, less than ideal environmental conditions such as poor water quality, overcrowding, stress by incompatible species etc, will create the conditions that may lead to an explosive & damaging outbreaks. The odd parasite is often present, and appears under good conditions, to remain dormant. Once however stress is caused by any factor an outbreak becomes almost inevitable, so remedial action is imperative.

These worms as in fact they are, obtain nourishment by “eating” skin fragments as well as the sucking the blood of the victim, this contributes to the pale appearance in chronic infestations.

The Hobbyist should suspect the presence of these parasites if he/she observes the natural colours of the fish appear to have faded, this is often concurrent with a clamping of the fins, or a folded appearance . Although in Gyrodactylus the infestation is more typically found on the skin, it often will manifest itself by attacking the gills. The parasite is about .75 mm long, & has at its anterior portion a sucker which has two central large hooks, surrounded by some sixteen smaller hooks for attaching itself to its host.

Gyrodactylus belongs to Phylum Platyhelminthes which are unsegmented flat worms, the Class or sub-division they belong to is Trematoda. This Class is again divided into 2 divisions viz. Monogenea & Digenea. Gyrodactylus belongs to the Monogenea, as it has only the need for one host, unlike the Digenea, which must have an intermediate host to complete the life cycle.

There are several varieties of Gyrodactylus , possibly the most common is G.elegans, others are G. medius, G. gracilis, but there are many more. All however have a similar life cycle, and cause for the most part identical symptoms. It is not therefore necessary for the Aquarist to concern himself with the species identification.

It is worthy of note however that there are salt water forms of this parasite viz. G.salaris as well as others, these can and do cause major problems form time to time in Salmon as well as other culture.

The sizes of the different forms vary just a little, from a low of about .3 mm, to a high of around .8mm. In some cases in early infestation they can be observed with the naked eye on the skin of the fish, but as the outbreak “deepens” the fish puts out massive amounts of slime, in a vain attempt to neutralize the parasite, this covers the organisms so that it is hard to see them individually.

A smear with something like a Q -Tip rubbed gently over the body of the fish, (holding same carefully but gently in a wet net), then applying the smear to a clean microscope slide, should enable the user, or even with a good magnifying glass, in the event that a microscope is not available, to make a certain diagnosis.

Typical signs of infection. Gyrodactylus & related species.

Water Less than optimum water quality, such as a lowering of the pH level, or high Nitrate or Phosphate readings can lead to an outbreak, stress caused by incompatible fish can also cause an outbreak.

G.salaris .Scanning electron photograph, shows parasite attached in typical manner to skin of Atlantic salmon. This method of attachment is similar for all forms.

Photo by courtesy of Dr. Mo. of Central Veterinary Laboratory Oslo Norway

Behaviour Fish will evidence lethargy, and swimming will become intermittent as the fish will tire very easily. Breathing at the surface, or just stationary “hanging” at the surface will be observed, as the fish try’s to obtain sufficient oxygen when the gills are badly infested.

Fins . Fins can become clamped and/or ragged . Often small spots of blood may be observed at the base of the fins.

Body Lesions may become apparent on the body as well as excessive mucous. Colours of the fish become “faded” in appearance.

Gills Gills will usually become protuberant and usually are paler than normal. Excess slime can easily be observed.

Skin . Areas of haemorrhaging can be observed as well as ulcers, which typically have a circular shape . A slime can be observed over the body in advanced cases.

Histo-Patholgy A scraping of the skin, or gills will invariably show signs of the flukes , which will confirm the suspected infection. Be aware that secondary bacterial infection is very usual due to the protective epithelial layers of the skin etc, being adversely impacted.

Life cycle The species multiply by sexual viviparous multiplication, but there is evidence that a form of parthenogenetic reproduction can take place inside the mature parasite, & even within the “daughter” cell. The term given to this rather unusual reproduction method is called “paedogenesis”. Although the parasite only gives “birth” to a single worm at a time, the gestation rate is so high that in a single month, under ideal conditions for the parasite as many as one million young can be produced. In this lies the danger that an outbreak presents, as far less than this number will cause massive mortality in the average Aquarium.

The newly born parasites can creep about on the skin of the host fish, or may search out a new host thus spreading the infestation. They must find a new host rather quickly or they will die, & this gives the Aquarist good opportunities to attack the problem, which if done quickly & correctly can have an excellent outcome.

Prognosis In most cases a cure is almost always possible, so the Aquarist should be aware of what to look for, and assuming that the problem is identified as a Gyrodactylus species that is causing the problem take remedial action as detailed below. If this is done, then losses can be and should be minimal. However if the problem is not discovered, until it has severely progressed, then heavy losses will almost certainly ensue. When the gills of the fish are badly damaged, or heavy necrosis of the skin takes place, the damage is often irreparable . It should be noted, that as in all parasitic infestations that cause necrotic damage, that secondary infection by bacteria and/or fungus may well occur. One author has suggested that the parasites themselves may carry the infectious bacterium from fish to fish.

Treatment . There are several treatments that can be successfully employed.

1) The use of Formalin . Use 2-4 ml of Formalin in 10 Litres of water, preferably in a separate quarantine tank, for 30 minutes. If fish show signs of distress stop the treatment. Alternatively Formalin can be used as an extended treatment in the Aquarium itself at a dosage of 15-20 ppm . Water should be changed after 3 days.

2) Methylene Blue can be used successfully at a dosage taken form a stock solution of 1 gram in 100 ml of water. Use 3-6 drops of this stock solution in a Litre of the water to be treated. Do not use this treatment in your main Aquarium as Methylene Blue, has a very adverse effect on the nitrifying bacteria, & also will cause the silicon bonding in your aquarium to become permanently dyed blue in colour.

3) Acriflavine is also very effective & is used at 1 gram per 100 Litres . ( We at Fish-Vet have a variant of this treatment with 3 active ingredients in our Fish-Vet product called Revive).

Other treatments have been reported as being effective, such as Benzalkonium chloride, Chloramine, as well as Potassium antimonyl tartrate. However there is not much current literature about the use of these, & I would hesitate to recommend them without more recent evidence.

To summarize then, Gyrodactylus in its various manifestations, is quite a common parasite, which if the fish are in good conditions, with clean water & unstressed, should remain at a level which will cause no problems. If for any reason these conditions should change for the worse, then an outbreak will often occur, which if spotted early can be brought easily & quickly under control.

Gyrodactylus is an excellent example, of how prophylactic treatment in a quarantine tank, can be used to preempt the likelihood of any such outbreak.

.

Brooklynella hostilis is found as a parasite in Marine Aquaria far more often than is commonly recognized as it tends to be overshadowed by the more frequent & well known parasites viz. Cryptocaryon irritans and Amyloodinium (Oodinium) ocellatum.

Photo of Brooklynella parasite. Note cilia all along the outer surface. X 400.

It like so many others is a ciliated protozoan which in many respects resembles its counterpart in fresh water Chilodonella ( see my previous article ). When conditions become favourable to its reproduction, very rapid multiplication takes place , reproduction occurs by simple binary fission, and such massive reproduction can and does cause fatalities , which is brought about by severe weakening of the host fishes.

The literature reports many differing species of fish as being susceptible, & the first reports of this parasite were related by accounts from some of the more prominent (at that time) Public Aquariums, such as the New York Aquarium Steinhart, etc.

Typical signs of infection Brooklynella hostilis

Water There is little doubt that fish exposed to lowered water quality , and in particular the stress of elevated Ammonia /Nitrite levels such as are brought about in shipping, can induce an outbreak of this parasite. All the literature seems to confirm this.

Behaviour Fish demonstrate lethargy, will “toy” with their food, appearing to eat & then spitting it out. Respiration becomes difficult as the Gills become heavily parasitized , & can easily be observed.

Brooklynella hostilis infestation on a Damsel fish. Note typical faded body colour, as well as severe erosionof the Dorsal & Caudal fins.

Body A “faded” appearance of small areas becomes apparent , & such areas spread outwardly as the infestation progresses. Sloughing of the epithelium will occur in later stages.

Gills Gills will become massively parasitized and a smear or other examination of the gills should easily determine the cause of the infestation.

Skin As the “sloughing” occurs increasingly large areas of damage can be seen, as the skin becomes broken down by the parasites activities.

Histo-Patholgy Parasite can be confirmed by skin or gill smears from suspected fish. Parasites are mobile and range in size from 60×80 microns to 40×48. In shape they are heart or kidney shaped ( see illustration), and they have typically ventral organ for attachment to their host.

Treatment

The literature has very little on effective treatment, & the authors disagree on the application of Copper as treatment, (Stopskopf’s book recommending its use, whilst Blasiola stating categorically it does not work). In this authors experience I have to agree with Blasiola, I have never found it to be effective against Brooklynella.

The combination of the following treatments & techniques have worked for me, on several occasions with varying degrees of infection, to eliminate the parasite, but I have had to employ at least 2 of the methods, and often all four. With careful attention the parasite can be brought under control( eliminated), but one should be aware there is no ” 24 hour” simple cure. Be very suspicious of anyone telling you that they have such a remedy.

1) Giving a “dip” in freshwater of the same temperature & pH as the Marine tank, for about 15 minutes ( careful observation must be made, during this time, to avoid distress, & the fish removed, if major problem is observed).

2) Giving a bath in Sea water with Formalin added add at a dosage of 1000 ppm for some 15 minutes.

3) Adding an Acriflavine product (such as Fish-Vet’s Revive) to the tank water for a period of 2 weeks after the above treatments.

4) Taking severe steps to ensure that water quality is optimum along with the TOTAL removal of any detrital matter .

I would mention that G.Basleer mentions in his book that Quinicrin gives a good result, regrettably he does not give any figures for dosage, or any contraindications.

If any secondary infections with by bacteria are observed then the use of an antibiotic would be useful. The use of UV to help prevent secondary infection should be employed.

It is useful to point out to the Aquarist who is intending to buy fish, that the judicious way to avoid to problems that this noxious parasite can bring to your Aquarium, is often best managed, by ensuring that your dealer has the fish in his tank for some 2 weeks prior to you taking it home. Most fish that will break out due to the stresses of transport , with this parasite will do so within this time.

To be fair to your dealer, you should show goodwill, by making it a conditional purchase, i.e. offer to pay for the fish, or at least part of it, provided he keeps it, and shows it is alright after the period of time mentioned has elapsed. Brooklynella is not an easy parasite to eliminate, so the effort to avoid it, is worthwhile.

I suspect that some of you as you read what would appear to be a depressing catalogue of parasites just waiting to attack your precious fish, may become disheartened somewhat, especially if you have had the misfortune to suffer one or more attacks in your early days in the Hobby. Therefore at the risk of been repetitive let me again emphasize that fish have an amazing ability to withstand infections, their immune system like most Veterbrates is well developed, & only when the conditions that we prepare for them or that they are exposed to, before we receive them are substandard, can we anticipate outbreaks which will adversely impact their health & our enjoyment of them.

Thus once again, everything you can do, to maximize the conditions in your Aquarium as well as ensure that you buy fish that have been properly collected, ( not with Cyanide for example), held in conditions at all stages of the collecting/shipping processes, can you reasonably expect to have little or no problem.

I can hear some of you saying to yourselves, “how can I know, how the fish are collected /shipped etc”. This is not easy, but careful reading of the literature, observing how your dealer handles his fish ( does he make any effort at quarantine etc), asking about his suppliers, (does he import directly, or buy from a wholesaler, ) does the wholesaler quarantine the fish etc. All of this will give you a far better idea of what to expect with the fish you buy. Furthermore, you should carefully observe how many dead or sick fish are evident in the dealers tanks, good dealers, who buy from good suppliers, will have far less than those that do not. All of this will enable you NOT to eliminate the risk, but greatly reduce it.

John Shawn Prescott. john@aquarium-gardening.com

Ref. 1 Aquaculture for Veterinarians . Pergamon Press. Ed. Lydia Brown 1993. Diseases of Fishes C. Van Dujin Jr. Iliffe Books Fish Medicine Ed. M. Stopskopf. W.B.Saunders Co

Refs.2

Fischkrankenheiten im Meerwasser aquarium G.Basleer Natur Books.

Disease Prevention & Control G. Blasiola F.A.M.A Mar. 1980 pp. 18-19.

Lom.J. Protozoan casing diseases in Marine fishes in A symposium on diseases of fishes and shellfishes. (ed. S.F. Sniezko) pp 101-123. Am. Fisheries Soc.

Lom J. & Negrelli R.F. Brooklynella hostilis . A pathogenic ciliate in marine fishes. Journal of Protozoology 17(2) 224-232.