Some of my wilds

Discussion in 'Discus' started by Rowland, Aug 2, 2007.

  1. Dirk B
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    Dirk B Aquascaper

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    Dear Peter,

    In biochemistry, a lot of effort is currently being put into understanding the reproduction cycles of mammals in particular (for contraceptive purposes in humans) and also understanding growth and its side-effect, obesity or being over-weight. From this research, we are beginning to understand the hormonal control of all of these processes much better, but we are also realizing that all of these systems talk to each other, in other words the one system influences the other. If you think about this, this makes a lot of sense and is quite logical actually. One system in the body cannot override everything else, then there would be no control. So, an animal has to grow to a certain size before sexual development can occur, and then sexual development will only proceed to its maximum, once growth has reached its maximum. In steroid metabolism in males, testoterone is produced in the testicles, but it is controlled by what we call a feedback mechanism, which means that as testoterone is produced it in turn will down regulate or switch down the production of testosterone by the testicles again. What then happens is that there is a steady and slow development of the testicles until they are eventually fully functional. All of the additional systems have slowly and in a regulated way contributed to the development of normal testicles that produce the required amount of sperm at sexual maturity. Now, if you add testosterone to the water of a tankful of discus it will be absorbed by the fish and start to stimulate the sexual development of the fish, such as colour, finnage and secondary mechanisms, but what it will also do is it will reduce the development of the tissues that would produce the testosterone, in other words it would reduce the tissues that will eventually produce the sperm. If you would in other words use this hormone and stop its use again, the poor fish would look perfectly male and macho, and go through all the spawning motions, but he can be perfectly sterile, because his testicles have not developed. In body builders that use testosterone, their testicles become completely reduced and they are sterile! After testosterone treatment, the reproductive system is now also out of synchronisation, and as these hormones are controlled by development, i.e. their growth is linked to the testicle development, one cannot assume that their testicles will ever "catch up", or develop normally again, so the chances are that the fish are permanently damaged and will only reproduce if manipulated from then onwards.

    Growth is also regulated by the body's own hormones and a steady and varying production thereof. Manipulate these and again the ripple effect is that you are manipulating the reproductive system.

    It is for these reasons that I will refrain from any manipulation, why mess with something that nature has balanced before so exquisitely? The driving force behind all of this manipulation is money. Fancier strains mean more money. Persons using these hormones are not interested in the wellbeing of their discus in the long term. Discus bred from manipulated fish may also have permanent genetic imbalances in their hormone production because they have not been selected for normal growth and reproduction. The result of this is what we often see, strains that cannot reproduce or grow normally.

    On your question about the production of a hormone by fish that stunts the growth of younger fish I can answer that I do not believe that there is one. What I can say though is if you are keeping discus at high densities, they will compete with each other quite viciously, and dominate younger fish to the point where they psyche them out of their food completely and they stop eating. The only way to get them to grow then is to separate them into smaller batches. What you always find though is that the biggest fish gets the most food and you must therefore feed a lot of food at each feeding so that they all can eat their fill, and another trick is to take larger dominant fish out of a batch and put them amongst adults "that put them in their place" and stop the bullying.

    I hope my comments will make you understand why I am so vehemently opposed to manipulation.

    Kind regards,

    Dirk
     
  2. ziyaadb
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    ziyaadb Algae harvester

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    eish im dizzy now from all of that reading
     
  3. Peter
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    Peter Algae harvester

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    Thank you Prof

    This has certainly been an eye opener to the usage of testosterone and your reply has really illustrated the reality of abuse to discus, puts the pieces together from a previous discussion with regards to ?the fancier the hybrid strain?, also now having respect, for the purist point of view.

    I was concerned with my fry and thanks for ironing this one out for me. I must say, until becoming more aware, I was designing my fry tanks around this problem. I did have some troubles with the larger fry, apart from dominating at feeding time, I would still have a fatality rate to find one or two small ones dead during the course of the day. I first thought it to be parasitic I spent a couple of hours looking for some ?tell tell? signs, but then witnessed the larger ones, killing the smaller fry from the last spawn. They have been separated since.

    Good question Rowland.
    Prof, from what I have read on the net, there has been a lot variations to what wilds would breed in. to the point of some believing it to be, so? ?again? from reading, Heckels in particular, will consider only breeding in a pH 5.5 or is said to have the best percentage of spawns at that level. If this were the case, why would it differ to that of hybrids or other wilds? I know this sounds like a silly question, but do Heckels live in different conditions to that of other wilds?

    Kind regards
     
  4. Dirk B
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    Dirk B Aquascaper

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    Hi Peter,

    I am glad that I have been able to clarify some aspects about the reproduction and growth, we can write a lot more about that as well.... but let us stick to the issues here.

    When it comes to raising discus, there is the tendency to try to keep them in large tanks of says 250 - 400 litres. From the management point of view of trying to keep smaller fishes in groups so that one can control bullying, this is not very helpful. I prefer to raise them in the cubes that I normally keep the adults for spawning, i.e. tanks that have a capacity of about 140 litres, dimensions 60 x 50 x 50 cm. What I can then do easily is effective water changes with having to change so much water, and then I can also keep an eye on bullying etc. If I find that the larger fishes are giving the smaller fish too much of a hard time, I move the larger ones to other tanks. The means that the ones left behind are not stressed from handling and can then develop unhindered. The large ones are the ones that have the best condition so they can best cope with the move in any case. I then move them to tanks where they are then together with bigger fish. So, in general, with a barrage of smaller tanks in the initial phases of raising you can much more effectively manage bullying and water changes, which I view to be major advantages. At the stage where they are 10 -12 cm, they can then be moved to the larger tanks so that they can grow out better.

    Kind regards,

    Dirk
     
  5. Dirk B
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    Dirk B Aquascaper

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    Hi Rowland,

    With regard to trying to stimulate wild-caught discus to breed, one should try to simulate what goes on in nature. Unfortunately, the English discus literature is not good is explaining what the natural conditions are, here the German literature, and particularly the older literature is much better. Unfortunately most discus literature today is a never-ending rehash of what everyone else has already written, very superficial, not applicable to SA conditions, and also does not properly explain processes in nature, so that is not a great help.

    What one needs to understand is that the Amazon basin has a very weak gradient, Manaus, which is 2000 km from the sea, is only some 8 metres above sea level. In winter, when it snows in the Andes, the water flow from the Andes is reduced and the water levels drop in the lower Amazon, the pH drops and the water temperature GOES UP. So in winter the water temps can be 32-34 C in shallow water areas. Then in spring, the snow starts melting in the Andes, and this colder water which has a higher pH comes down in a flood. So in spring and summer the water is actually COLDER! Because of the weak gradient, the water cannot flow to the sea that quickly and the Amazon overflows its banks and the forest becomes an underwater landscape. This is the time during which discus breed. SO, the stimulus for discus to breed is a rise in pH, and a drop in temperature. Does this remind you of something? When have your discus spawned? Invariably after a water change and that causes a pH rise and a drop in temperature. Additionally, I am convinced the low air pressure triggers spawning, in the Cape, when we have a cold front coming through, my discus wake up and start looking at each other! So, for conditioning discus, it is good to keep the water conditions constant but once the fishes are adult and in good condition, they can be stimulated to spawn by targeted water changes, just for starters.

    In my recirculating system, I battle with dropping pH all the time due to our soft water on the one hand and due to a fairly high stocking ratio, and good feeding. For me it is therefore not a problem to keep fish at a low pH, you should actually also find that your pH should drop all the time as well. How are you measuring pH? If not with a reliable pH meter, then your readings may not be correct. Once you have the fish in a good condition, you can try to do targeted water changes as described above in trying to stimulate them to spawn. It may need a number of such water changes before the fish will spawn, but that is what I would do.

    Hope that it brings you some success.

    Kind regards,

    Dirk
     
  6. Andre
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    Andre Green fingers

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    Hi guys

    I think this tread has some very useful information regarding discus, so I will pin it as a "sticky" thread.
     
  7. Peter
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    Peter Algae harvester

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    Hi Prof

    I couldn?t find my study notes in time during the last postings on Testosterone to contribute more to the topic, a few years ago I was asking the same questions regarding its usage. Trying to get a better understanding of all these ?hormonal things?.
    From what I have read, we (the human race) have come along way in improving manipulation in all aspects, where science has played a vital role in it?s development to the benefit of us all, to the manipulated meat and vegetables we have on our plate. Though I understand, that some methods used are not everybody?s cup of tea (which I humbly respect) but there has been importance for these types of development. Sadly?South Africa is like a big ?discus restaurant? (don?t hurt me for saying this) but nobody cares what happens in the kitchen, but only look to what?s on their plate.

    Please?I?m not voicing my approve or disapproval but merely saying, there is so much info and a lot gets interpreted by those who read it, to their understanding of the topic and it then gets interpreted by those who read it and so on and so on. To a point of utter frustration of myself (and others) taking road trips to no-where. I really appreciate in you taking time-out, to help us in the hobby and through discussion like this makes the discus hobby not only interesting but fun as well.

    Here is a quote to a question I asked Andrew two years ago.

    I understand the sensitivity here and in honesty, trying to tip toe through this section.
    What keeps popping up my ?reads? is the difficulty of spawning ?wilds? and ?101? ways to be successful at it
    I thought maybe it to be easier to bring ?wild? youngsters and growing them out, possibly making them less wild and more ?willing? to spawn?

    Kind regards
    Peter
     
  8. Dirk B
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    Dirk B Aquascaper

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    Hi Peter,

    This discussion is taking place on a forum, and as a result of that everyone is entitled to an opinion, and you obviously have the right to voice an opinion, and I respect that. I can give advice and it is up to the reader whether he/she wishes to accept or reject it, I don't have a problem with that.

    I have explained my opinion on hormone use, and as I indicated, I maintain that any use, even a single use of a hormone such as testosterone can have lasting effects. These hormones bring about certain effects such as stimulation of colour development, but they also influence tissue development permanently. So for me the question is, if you have say successfully manipulated a female discus by the use of testosterone once and she does not want to spawn again, do you do so again? If you have the hormone on your shelf, I maintain that it will be used again and thereby a female that may have a genetic defect in her reproduction is now manipulated into producing offspring thereby transferring this genetic defect to her offspring.

    Let us say that you are someone like yourself, Peter, very enthusiastic about discus, and now you want to start of keeping discus and hope that you may one day be able to breed them. You invest a lot of time in reading up about discus and buy a lot of books on the topic. You go to a shop in Johannesburg and buy some discus for the first time. These fish look healthy and colourful, let us say they were of the strain that you had wanted or dreamt of. You buy them for a lot of money, invest a lot of money in equipment and food etc. and finally get the fishes to breeding size. Now the fish just simply refuse to spawn, and you are frustrated to the point of despair. You simply do not know about the manipulation that the fish were exposed to before they got to you. Is this fair on the average enthusiast? My opinion on the matter is that it is not. Given the money one spends on discus, you have the right to demand fish that can grow normally and reproduce normally. Why not? What you have been sold is a defective product and is tantamount to fraud in my opinion. Why is the manipulation done? Just simply for financial gain. If you are first one to produce some or other colour strain, you may be the first one to market it and make a lot of money as a result. Thus this type of discus keeping has become a racket as far as I am concerned.

    You may ask, why I react in this way? I have had literally hundreds of telephone calls and emails over the twenty years that I have been keeping discus, about discus problems that persons have, and many of these are related to hormone use behind the scenes. Advice from the trade is then often even worse in that they then say that the fish are not breeding because the water conditions are not right, they want to sell you more equipment, say a RO unit and then a bigger and better filter and so it carries on, you are the poor sucker eventually. And what happens to the bloke who bred the defective fish in the first place? Nothing, his bank account gets bigger and he has conned the market, so one can breed these fish without the manipulation, and he has the market monopoly.

    It is exactly this that has lead to the swing back to keeping wild-caught discus, at least you are gauranteed of non-manipulated fish and have a good chance of getting the fish to breed. And if they are normal non-manipulated fish they should respond to natural stimulation to breed, and there should be no need to use hormone manipulation.

    I hope that you can perhaps now understand why I am so opposed to the use of hormone manipulation and it is not some or other personal vendetta that I have against its use, I actually have the interests of the general aquarist at heart.

    Kind regards,

    Dirk
     
  9. Peter
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    Peter Algae harvester

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    Hi Prof

    Thank you for hearing what I was trying to say. Hopefully those who aren?t familiar or wanting to play with the ?hormonal? influence, now understand how detrimental it can be?.

    You have touched on my next question, as it has become ?racketeering? business, there are no guarantees of the sincerity of some overseas breeders or some local for that mater. (please? this is not an attack on breeders but purely to express my degree of trust, given in these current circumstances)
    I have invested in some lovely discus with intentions to breed them locally, fully aware of the possibility of ?influence? but on the other hand trusting the word of the breeders? of ?no need to worry.? or ?I do not hormonal feed? still makes it a tough buy. This LED to my questions in hybrid vigour, hoping to ask a question related to this discussion, ?could this ?influence? be out crossed??? I?m trying to find out, if future generations will be affected or be normal?

    On the lighter side?.next time I meet a bodybuilder, I can smile, knowing I have two things bigger then what he has?lol

    Kind regards
    Peter
     
  10. Rowland
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    Rowland Algae harvester

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    Your brain and what else Pete??
     
  11. Peter
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    Peter Algae harvester

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    Hi Rowland

    Sorry for the questions on your post, feeling a bit embarrassed for asking so many.
     
  12. Rowland
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    Rowland Algae harvester

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    Hey Pete

    I am more than happy to "host" all those questions and answers. I cannot tell you and Dirk how much I have learn't from just taking a few photos of my wilds. Really appreciate such insight and generosity of giving advice.
     
  13. Peter
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    Peter Algae harvester

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    Thanks Rowland? it has been quite a digression on topic. I have one last question?lol, regarding ?pheromones?. Do brooders release this during spawning? does it exist?, if so, does it influence others to spawn? lots of hobbyist speak of this but i have found nothing to confirm it.

    Promise, no more questions after this...

    Kind regards
     
  14. Dirk B
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    Dirk B Aquascaper

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    Hi Peter and Rowland,

    To the earlier question that you posed, Peter, about whether one can breed out hormone induced defects again: If the fish were only hormone treated and one manages to get a spawn from such fish and then raises the offspring without hormones it should be possible to get them to breed normally again. Fish that have a genetic defect say in reproduction (which is often why hormones are used in the first place) will retain that defect. Possibly you may be able to cross that out through introducing "new blood" but this may take a few generations of battling with low numbers of fry and hardly worth the effort. Also, outcrossing is a different concept to getting hybrid vigour. Hybrid vigour is the result of crossing two inbred strains with one another and then getting a hybrid fish that is much stronger than either of the parent strains.

    On the release of pheromones by discus specifically, all I can say is that I do not know, and I doubt whether anyone really does. You would need a pretty fancy lab to analyze this. Pheromones are compounds that are produced at very low levels, and yes, in mammals it is known that they play a role in mate attraction i.e. a reasonably specific signal. What I observe in discus is that a very important signal between fish is the visual signal. Even fish that are separated in two tanks, in which they would not be able to communicate via pheromones if these were transmitted via the water, I have often observed that the fish shimmy at each other and are attracted by each other.

    Again, I think one should look at what happens in nature. I believe that there the fishes move around in large shoals and a dominant male will choose a female and they will separate from the shoal and spawn somewhere in peace and quite. This would let the next male in the shoal become dominant and so the cycle could repeat itself. Thus in a group of discus kept in a tank, the dominant male and a female will pair off. If you remove them, then the next pair will pair off. All of this is however critically dependent on nutrition. If your nutrition is not spot on, then the fish will not reach the condition required for spawning and even if they then spawn they will be more likely not to fertilize the eggs properly, or take care of the fry properly etc etc. The adults need good reserves of energy before they can spawn and raise young because they put a lot of energy into the egg-laying and sperm production, and they also have to put a massive effort into the slime production. If they are not in prime condition, they are actually damaging themselves by spawning, and they will not make a success of raising a spawn.

    So, happy feeding your discus to prime condition.

    Oh and Rowland, I think Peter was referring to the two halves of his brain that were larger than the bodybuilders, or am I misunderstanding something here?

    Kind regards,

    Dirk
     
  15. Peter
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    Peter Algae harvester

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    Thank you Prof Dirk

    Well?coming back to Rowland?s questions, I figured in doing some exploring of what their natural environment prams are, hoping to get a better understanding before trying to simulate these conditions.

    Having taken a fancy to the "Cabeca Azul" (Blueheaded Heckle) as Prof mentioned, had me curious on how they would look (still need to find some pics), found some ?reading? on the Rio-Negro to a place called ?Igarape Zamulo?, supposedly the only waters they inhabit. The water temp was 26, however, I?m sure in the river, there is a number of fluctuating currents (also ?read? some where) possibly each having temp and pH variations all in the same ?river flow?? with certain entry streams at Manaus with a pH from 2.5 and 4.5 and in some ?lakes? pH 2.8 (wow? this is low) to water temp 28/29, air temp 34 and conductivity of 80 microsiemens (this is also low). So no trace elements here?and get their nutrients from what?s ?swimming around?, (also read some where) no wonder some ?fresh caught? look so thin!!

    Further down the Amazon, at Belem to a place called ?Rio-Xingu? (home of the brown?s) here the pH is noted at 6.5 with conductivity of 120. and in a town called ?Tefe??mmmmm, here the pH is 5.2 - 6.2 water temp 28-29.

    Very interesting these variations. But I can't find info as to how rain contributes to stimulation? but feel the water must be "very acidic" for breeding to begin with?

    Back to the bodybuilder.....you guy's are way off...no cigar.
     
  16. Dirk B
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    Dirk B Aquascaper

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    Hi Peter,

    This time I am going on strike. I have a German book of 215 pages on the waters of the Amazon and its inhabitants called "Diskusfieber" (translated discus fever) by Hans J Mayland, so I am not even going to attempt an answer about which water parameters are found where. This book has a reading for each river in a number of places, and these readings also change during the year as I indicated earlier.

    You also need to brush up on your Brazilian Portugese, an "Igaripe" is an area adjacent to the main river which gets flooded when the main river floods. Then "Rio" is a river and not a place, so the Rio Xingu is a major tributary of the Amazon. The town is called Tef? and is pronounced 'Tefay' and this is the home of green discus, not browns.

    English literature is useless as I explained earlier about the rundown after the winter, it rains just about every day in the Amazon and rainwater will not raise the pH. And finally, wild-caught discus have bags of food that they eat every day in the Amazon, they eat shrimps all day long and veggies and other things and they definitely are not emaciated when they are "fresh caught". They are emaciated by the racket team, the Brazilian exporters now feed their fish a lot better than before and they arrive in South Africa in good condition, it is the South African wholesalers and the petshop owners that give the fish that thin look because they know very little about maintaining and feeding discus properly, and they will pass their problems on to you at the drop of a hat and blame you for mistreating them when they die on you. You must please excuse my sarcasm about the South African side of things, but I have seen this repeatedly, and again it is part of what gives discus the reputation of being so difficult to keep. The fish that Rowland is now going to import, that have been properly quarantined and conditioned in Holland will arrive here in excellent condition, I have no doubt. Check out the website of Amazon Exotic Import http://www.goslinea.com/ in Germany to see what wild-caughts CAN look like if looked after properly!

    Kind regards,

    Dirk
     
  17. Peter
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    Peter Algae harvester

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    Hi Prof

    I don?t blame you on this one ...lol, I had a look in that direction and saw Pandora?s Box beginning to open, so shall rely on their information to the different pH areas and not how and why. I?ll save this for another time. but? Ist diese buch bekombar in S.A., in Englisher text wenn nicht dan muste ich auf meine frau?s vertaaling aufhanglik wees.

    What I?m thinking, that possibly each wild would have their own criteria in stimulation related to their area? I find that Hybrids on the other hand quite relaxed to any pH, just that the higher the pH the lower the hatch rate. So when I need to out cross with wilds at a lower pH (still under the impression it?s required), I?m sure my hybrids will adapt easily, this is my whole motivation in learning to meet and understand the needs of wilds and their differences/comparisons to that of hybrids.

    I found this one hobbyist method of conditioning water for Heckels. He mentioned that they happily breeding between pH 4.8 - 5.8. GH and KH combined to be about one. My concern here is the stability of the water should they take along time to spawn?

    This is his ?mix? for 200lt conditioning.

    75% RO
    25% Tap
    Adjusting with acid in reaching pH 4.5 ? 5
    Peat moss.

    He then does 10% daily w/c and they start to show interest and he continues like this until spawn, when at wrigglers he reduces to 5% w/c. he does mention that after 20 days he slowly brings up the water parameters to a more stable level.

    Don?t laugh?but I look at all these methods as possible guidelines to help me. Now in the same breath?is this another infamous road to know where, meaning, spawning parameters should be the same for all discus, just different ?things? to trigger them to start?

    King regards.
     
  18. Dirk B
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    Dirk B Aquascaper

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    Hi Peter,

    This thread is becoming exhausting.....

    Let me begin where you end off in good Chinese fashion. No, all discus do not require the same conditions for breeding, but they do not differ that much.

    The recipe that you suggest for your water mix is a recipe for disaster. pH is important, but is of far lesser importance that the chemistry that decides the pH, i.e carbonate hardness and after that calcium and magnesium content. If folks in Europe, where water is hard, i.e. high in calcium carbonate and magnesium in most areas, were to dilute their water with 3 parts of RO, they would not achieve the desired soft water for breeding most discus, not even to speak of Heckels. In Cape Town, where we have soft water coming out of the tap, you would have a much better chance of success with that sort of ratio. With water that is as soft as that you are going to have problems with plastic pH, that cannot be changed if you are working with soft water. Also although the pH for breeding of discus should be acidic, it plays a far lesser role than total dissolved solids in the water and critically the amount of carbonate.

    As a general statement one can however say that wild discus will demand softer water for breeding, whilst tank breds can cope with slightly harder water, but still not typically hard European water. As European water and water in the USA in most areas is hard, whilst in many areas in South Africa is soft, most of the literature does not apply to SA conditions and you need to go through a major mind shift in keeping discus in SA.

    Finally, I want to explain a few things about how discus were bred in captivity for the first time and how this actually came about. In the post war years in Germany, there were major advances in understanding water chemistry in natural systems. This was pioneered by a Prof Rolf Geisler, a professor of limnology at the University of Freiburg, Germany. He wrote a pioneering book on water chemistry for the aquarist in 1964, called "Wasserkunde f?r die aquaristische Praxis" (translated "Practical water science for the Aquarist") as he also was a keen aquarist. He also published numerous articles about cardinal tetras. He happened to have been a student friend of my aquaristic mentor here in South Africa, Mr Georg Reinhardt (died in 1998), formerly of the Pretoria Aquarium. The father of discus breeding is Dr Eduard Schmidt-Focke who successfully bred discus somewhere in the early 1960's (not Jack Wattley who visited Dr Schmidt-Focke regularly to tap into his knwoledge and obtain fish from him!). He had received a lot of advice from Prof Geisler in getting the water chemistry right. When I started keeping discus in 1988, Mr Reinhardt organized for me to visit Dr Schmidt-Focke (by training a gynocologist) in 1990, during one of my scientific visits, through his connections with Prof Geisler and this was a major eye-opener for me. He explained to me that his father had run a tropical fish importing business which his brother had inherited, but it was through this connection that Dr Schmidt-Focke was able to obtain his first discus. Prof Geisler helped with the water chemistry and this lead to the first breeding of wild-caught discus. Soft water on the one hand, and good nutrition on the other were found to be the key to success. One of Dr Schmidt-Focke's early successes was to cross a Heckel discus with a blue discus which has lead to the modern day brilliant turquoise and eventually blue diamond strains.

    But key to this all was understanding the natural water chemistry and if you want to make a success of discuskeeping you must understand this as well. Prof Geisler's book is key to this, but long out of print. The other good book is "Diskusfische - K?nige Amazoniens" (discus fish - kings of the Amazon) again by Hans J Mayland (1981) and then the other book by the same author that I mentioned earlier are also crucial in developing an understanding of the natural conditions required for keeping discus. However, your poor wife is going to have a hard time to translate all this.....

    If you guys really want to twist my arm, I may be prepared to give lecture about the topic in Johannesburg at some time when I have to visit my research funders again.

    Kind regards,

    Dirk
     
  19. dart
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    dart Green fingers

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    I'm surprised no one has done any twisting yet :)

    I'd be very interested!
     
  20. Peter
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    Peter Algae harvester

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    Hi Prof

    I must apologize for this exhaustion, but to read what you have to say is always encouraging and is very helpful to my understanding more on discus. To read your post on the roots of discus history is a definite highlight of this thread. Thank you for the book titles and your willingness to lecture, I?ll look to Andre and Cameron in creating awareness, so collectively we can twist your arm. as dart has already started..lol

    Kind regards
     

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