Hybrid Vigour

Discussion in 'Discus' started by Peter, Jul 27, 2007.

  1. Peter
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    Peter Algae harvester

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    Hi

    Having a fundamental understanding on the genetic side of discus, there is such array of mix’s / "formulas"
     
  2. Andre
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    Andre Green fingers

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    Hi Peter

    Some fish seem to be much more resistant to inbreeding depression than humans and some animals seem to be. Some lines can be crossed in quite a few generations without any mayor problems. However, the difference is amazing when you then cross these out to unrelated lines.

    Dirk recently crossed some of his line of angels with some wild type angels that Nick James brought in for me from Czeckoslovakia and the resultant offspring are really amazing.

    Depending on the strain that you are going for it might be a good idea to start a new line when crossing out and using offspring from the new line to cross back to your current line. This way you wont have to start from scratch every time you cross out.
     
  3. Dirk B
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    Dirk B Aquascaper

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    Hi Peter,

    Here I can give you some pretty precise advice with regard to discus. I visited Dr Eduard Schmidt-Focke in 1990 and discussed this exact question with him then. He has also written about this in his book on discuskeeping.

    He experimented with inbreeding in a number of strains that he created, notably his red turquoises, and brilliant turquoises. What he found was that through inbreeding he could "fix" a strain but that by generation 5 to 6 the fish started to get smaller and egg clutches were getting smaller and fertility became an issue.

    Having said this though, I am also aware that Manfred Goebel has been breeding Alencer Reds from fish that were originally bred for the first generation by Dr Schidt-Focke in 1989, and has been not breeding in new blood ever since that time. He has tried not to breed brothers and sisters with each other and has tried to keep this strain more outbred, but with small numbers you cannot but get into inbreeding. He now has this strain in its seventh generation and instead of getting smaller, or less fertile (and the strain had excellent fertility and large clutches to start of with) the adults are now larger than they originally were through selection for size and egg clutches and fertility have not dropped.

    What one learns from this is that it actually depends on the material that you start with as to what the effect of inbreeding will be. If you start off with fish that already have breeding problems, then those will invariably get worse. If you start off with big healthy no nonsense fish and breed selectively, inbreeding may not have drastically negative effects.

    If one looks at the early blue diamonds that appeared on the market, these were terribly inbred, never more than 50 eggs per clutch and many males totally infertile or only maturing at a higher age. Now there are some strains of blue diamonds that have good fertility and larger clutches, it just depends on where they came from.

    One thing that I would like to add is that I all to often see pairs of fish that are breeding with each other that have no hope of producing something that it going to be "interesting" or an "improvement" of strains. This often comes from persons keeping fish from all sorts of backgrounds and then fish pairing off randomly. The mongrels these produce are totally useless and lead nowhere. I would therefore advise anyone that is seriously considering to breed discus to get a group of fish of the same strain and to then try to establish pairs from them and to finally perhaps breed from them. In this way the offspring can then be sold as blue diamonds, or leopard snakeskins or whatever fly by night names you might want to give them...... and believe me, I am sick and tired of all the names, and for that matter many of the new strains look absolutely appalling to me, and I really feel sorry that discus have been bred into these color forms that are so far what they originally looked like in nature.

    The advice that Andre gave about backcrossing fish is good and is a practice that is often used.

    But you only need to get worried when you reach 5-6 generations, and I have yet to see anyone in SA breeding discus for those number of generations.....

    Kind regards,

    Dirk
     

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