Breeding Siblings and Robust Genetics

[aquagal]

I notice a lot of people on this forum buy a group of discus, that I presume are from the same hatching, to breed themselves. Aren't the offspring of these related fish weaker genetically than the offspring from two unrelated fish? I assume this would be rare in nature? Seems like this could be a major contributor to the "delicate" constitution found in discus...just wondering?

Sherry

[OIF03VET]

I dont have an answer for you but I have been wondering the same thing myself for quite some time. I look forward to getting an answer.

[Rod]

When we inbreed what we are doing is aligning genes, basically you are concentrating genetic traits. From the point of view of strain development this is the simplest and quickest way to develop a homogenous strain. But it is a double edged sword, although easier to create a desirable strain it also concentrates negative genes and without careful selection of the brood stock, any fault in the line is also quickly concentrated. I think almost every discus available on the market has inbreeding in its makeup, and there are many excellent strong healthy strains resulting from these breedings. Equally there are many very dodgy strains as well. Many breeders practise a technique known as line breeding, this form of inbreeding retains a larger genetic diversity by breeding cousins and other not quite as closely related individuals together. And many breeders are always on the lookout for new 'blood' to breed into the line, to outbreed as it were. Strict selection of the brood stock and a certain amount of good luck are required to develop a successful inbred strain.

HTH

Rod:)

[OIF03VET]

I was reading somewhere online that it is benificial to try and breed in wilds from time to time. It mentioned that Heckels were the best since there genetics are the most unique of the wold strains. My question is how long would it take to get your varieties to breed true after you have introduced such a differnt fish into the mix. It seems like it would take many generations to breed the prominent Heckel bar out esp if you were working on a leopard SS or even more hard would be a solid pigeon. If I find the articles I was looking at I will post the links.

[OIF03VET]

Here is one article I found

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T4D-3W1YFCR-1F&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=93bd29353fe0464cc80ec6be6566cd72

Trial-and-error method has been used extensively in the breeding of Discus. There is limited knowledge on the genetic structure of its species complex and also the genetic basis of its stock constitution and management. Random Amplified Polymorphic DNA (RAPD) fingerprinting was used to assess the genetic diversity among four wild forms of Discus: Symphysodon discus (Heckel), S. aequiefasciata aequiefasciata (Wild green), S. a. axelrodi (Wild brown) and S. a. haraldi (Wild blue) and five cultivated varieties of Discus (Turquoise, Pigeon, Ghost, Cobalt and Solid Red). The Mann–Whitney U-test used in the comparisons among the inter-wild form, inter-cultivated variety and between wild form and cultivated variety similarity indices revealed that the gene pool of the cultivated varieties of Discus is smaller than that of the wild Discus forms. Unweighted pair–group method with arithmetic means (UPGMA) phenogram showed that the Heckel Discus (S. discus) is genetically the most divergent in relation to the other three wild forms, being 2.89 times further in mean genetic distance from the other three wild forms (Wild green, blue and brown) than Wild green to the other two wild forms (Wild blue and brown). The cultivated varieties is 3.18 times genetically closer to the three S. aequiefasciata wild forms (Wild green, blue and brown) (mean genetic distance=0.033) than to S. discus (Heckel) (mean genetic distance=0.105). This suggests that the S. aequiefasciata wild form is the more likely genetic origin of the cultivated varieties. In addition, there is no distinct clustering of individuals from the same cultivated variety indicating the lack of a genetic basis for the present phenotypic classification of the cultivated varieties. Outcrossing with the wild forms especially, the Heckel Discus is recommended to increase the level of genetic variability in the cultivated varieties.

[Peachtree Discus]

with the current state of the hobby i feel there is too much competition/supply for a small time breeder to really establish themself. Right now i run about 10 tanks and i doubt that i will ever have the system/space to support some 100+ tanks. (system seems to be the biggest issue)

therefore, i have been thinking about this type of breeding. i have been researching this topic and wondering...has anyone on simply had any experiences with this style of breeding? were you able to isolate any specific traits? did you introduce any problems? how many generations deep have u gone? any valuable mentions?

[AADiscus]

I will speak from a small time breeder. You can breed quality discus from bro/sis, mom/son, etc. (I would not recommend for alot of spawns though)

However, after a couple spawns we will put another fish that is not from that group in there to spawn to put different genetics in there. After that you keep cross spawning with everyone as they grow older. That is why a breeder will keep at least 8-10 fish from a spawn to there selfs. :D

[Peachtree Discus]

......That is why a breeder will keep at least 8-10 fish from a spawn to there selfs. :D

the 8-10 that you are keeping, are those the 1s where you would be trying to isolate traits? or would they be the "pick of the litter" that you are keeping for urself?

i am really thinking to try this method to isolate traits. has any1 ever attempted 5+ generations with mutts? :antlers: + :mickey: = :jester: :jester: :jester:

[Condor]

When we inbreed what we are doing is aligning genes, basically you are concentrating genetic traits. From the point of view of strain development this is the simplest and quickest way to develop a homogenous strain. But it is a double edged sword, although easier to create a desirable strain it also concentrates negative genes and without careful selection of the brood stock, any fault in the line is also quickly concentrated. I think almost every discus available on the market has inbreeding in its makeup, and there are many excellent strong healthy strains resulting from these breedings. Equally there are many very dodgy strains as well. Many breeders practise a technique known as line breeding, this form of inbreeding retains a larger genetic diversity by breeding cousins and other not quite as closely related individuals together. And many breeders are always on the lookout for new 'blood' to breed into the line, to outbreed as it were. Strict selection of the brood stock and a certain amount of good luck are required to develop a successful inbred strain.

HTH

Rod:)

Rod, hope you don't mind, I quoted you on Simply Cichlids.:D


Here is one article I found

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T4D-3W1YFCR-1F&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=93bd29353fe0464cc80ec6be6566cd72

Trial-and-error method has been used extensively in the breeding of Discus. There is limited knowledge on the genetic structure of its species complex and also the genetic basis of its stock constitution and management. Random Amplified Polymorphic DNA (RAPD) fingerprinting was used to assess the genetic diversity among four wild forms of Discus: Symphysodon discus (Heckel), S. aequiefasciata aequiefasciata (Wild green), S. a. axelrodi (Wild brown) and S. a. haraldi (Wild blue) and five cultivated varieties of Discus (Turquoise, Pigeon, Ghost, Cobalt and Solid Red). The Mann–Whitney U-test used in the comparisons among the inter-wild form, inter-cultivated variety and between wild form and cultivated variety similarity indices revealed that the gene pool of the cultivated varieties of Discus is smaller than that of the wild Discus forms. Unweighted pair–group method with arithmetic means (UPGMA) phenogram showed that the Heckel Discus (S. discus) is genetically the most divergent in relation to the other three wild forms, being 2.89 times further in mean genetic distance from the other three wild forms (Wild green, blue and brown) than Wild green to the other two wild forms (Wild blue and brown). The cultivated varieties is 3.18 times genetically closer to the three S. aequiefasciata wild forms (Wild green, blue and brown) (mean genetic distance=0.033) than to S. discus (Heckel) (mean genetic distance=0.105). This suggests that the S. aequiefasciata wild form is the more likely genetic origin of the cultivated varieties. In addition, there is no distinct clustering of individuals from the same cultivated variety indicating the lack of a genetic basis for the present phenotypic classification of the cultivated varieties. Outcrossing with the wild forms especially, the Heckel Discus is recommended to increase the level of genetic variability in the cultivated varieties.

OIF03VET, hope you don't mind, I referenced this article on SC as well.

Good thoughts and discussion everyone.:)

Adrian

[OIF03VET]

No problem Adrian. Share the knowledge/openions!

[Rod]

Rod, hope you don't mind, I quoted you on Simply Cichlids

Adrian

Hey no problems, glad to help. :)

[AADiscus]

Wes, we will normally keep the pic of the litter for ourselves (not all times though, lol;)) Once we get a confirmed pair of 1 or 2 we will sell off the rest.

[baby blue]

It's stated that some breeders pair many discus of the same spawns for at least 3 generations F1, F2, F3 but nothing happened. But for the next breedings, they change because it has affect at this stage, anyone has some thought of this?

[CliffsDiscus]

It's stated that some breeders pair many discus of the same spawns for at least 3 generations F1, F2, F3 but nothing happened. But for the next breedings, they change because it has affect at this stage, anyone has some thought of this?

Usually F3 the Medelian generation will start to kick in.