BN Crossbreeding...

[SilverBlade86]

I'm still looking for reasonably priced BNs or GBAs around Chch, and I noticed this auction:

http://www.trademe.co.nz/Home-living/Pe ... 189492.htm

Question, it says the mother is a GBA and the father is a normal BN, if I understand it correctly. Does this affect the fish in any wa? Eg what can I expect from breeding them, etc etc.

Thanks for the help in advance.

[alanmin4304]

I suspect that the gba is a recessive gene in which case you will get from breeding to each other: 25% gba, 50% normal split to gba and 25% normal. The problem is that you probably can't tell which is normal and which is normal looking but split to gba. This can be usefull to strengthen the gene pool in a recessive fish like an albino but the other than albino fish are often destroyed. If you bred these to a gba you would get 50% gba and 50% normal split to gba.

[purplecatfish]

If the Parent generation GBA is recessive (aa) and the Normal is dominant (AA) Then:

Generation 1 will all look normal but will genetically be (Aa)

Generation 2 will have 25% GBA and 75% normal looking although the genetic makeup will be 25% aa, 50% Aa, and 25% AA.

this does make quite a few assumptions such as only one gene being responsible for the golden colour.

[SilverBlade86]

I dont get it. Could you please explain that in normal English please? Sorry, but biology isnt my best subject. :oops:

[Jasmine]

If the Parent generation GBA is recessive (aa) and the Normal is dominant (AA) Then:

Generation 1 will all look normal but will genetically be (Aa)

Generation 2 will have 25% GBA and 75% normal looking although the genetic makeup will be 25% aa, 50% Aa, and 25% AA.

this does make quite a few assumptions such as only one gene being responsible for the golden colour.

It means generation one will look like the normal bristlenose, but carry the golden gene.

If you cross generation one to a sibling, you have a 25% chance of getting golden, 50% chance of getting normal bristlenose carrying the golden gene, and 25% chance just normal bristlenoses.

[purplecatfish]

Sorry, i'll try again.

The thing to remember in genetics is that the appearance is different to what the genes actually are because a dominant gene will mask a recessive one.

If a fish has two recessive genes (aa) for a trait e.g. golden colour then it will be gold. But if a fish has one recessive and one dominant gene (Aa) it will look exactly like a fish with two dominant genes (AA).

When you cross two fish with (Aa) characteristics you get offspring who carry the genes in the following proportions: 25% (aa) 50% (Aa) and 25% (AA) but their appearance is 25% recessive and 75% dominant.

You can determine the difference between (AA) and (Aa) by making a cross with (aa). The first will only produce offspring with dominant characteristics the second will produce 50% recessive and 50% dominant with mixed genes (Aa).

But I would like to add these percentages are best shown in a large population.

Hope this helps, please ask if it's not clear.

[fishboi]

for SilverBlade86 [correct them if their wrong pplD ]

this is how i under stand it.

Chromosome is the structure that carries the genes.

dominate is a gene that expresses itself visually in a single does. [in this case it expresses in color]

Recessive is a tricky one and often relates to albino. its a gene that must be on both chromosomes of a pair in order to be visually apparent. except when the gene is carried on the sex chromosome [a sex linked gene where no locus exists on the other sex] basically it has to be chromosome of a pair so there is no dominant gene to mask the recessive presence.

sometimes genes are carried on the sex but since all I've ever seen on this cross is female GBA with a male BN i have no idea. but the mix is what we call an incomplete dominance, this is when the dominant gene is not able to fully suppress the recessive gene and as a result both gene is displayed. so the first generation shows appearance of both colors.

[fishboi]

just reread my post and left this one out which mite help.

Locus is the fixed position where a gene is located on a chromosome.

[SilverBlade86]

Oh now I get it! So either ways, by breeding ones from the auction, it will be possible to get a few normals, GBAs and normals with the GBA gene.

Thanks for the help guys. I think I'll go place a bid in the auction. Since they cant be sexed yet, how many should I get? 3-5? Keep in mind my 3footer is not ready yet and they can only go into a 1.8ish f tank thats being shared with a 3 guppies, 4 WCMMs, 3 swords and 2 fighters. I do have a spare tank lying around, but I doubt I can find any driftwood for them.

Edit: Also, is the fry a GBA with BN colours or a BN with GBA colours? :lol:

[purplecatfish]

Also, is the fry a GBA with BN colours or a BN with GBA colours?

Depends on the generation :lol:

When choosing a group with the hope of a pair the usual choice is 6 because it gives a 96.875% chance of getting a pair. 5 will give a 93.75% chance; 4 would give a 87.5% chance. (Do you want to be confused with the maths? :lol: )

[Dixon1990]

Digging up a old topic...Again! :lol:

Arent common Bristlenose and GBA a different species (not just a different strain)?

[HummingBird]

Yes, they are a different species, and a lot of people object to their being cross bred.

[Dixon1990]

:evil:

[Cheesejawa]

I have heard that the original GBA that was found in the wild was bred with an ordinary BN, making some of the offspring GBA and some ordinary BN and then line bred until the the BN Gene was out bred and creating the GBAs we have today.

Wouldnt this mean that all GBAs are part BN and therefore crossbreeding would not create hybrids but rather unpurify the strain. I have also heard it is hard to find a GBA in New Zealand that wasnt some part BN.

Im not saying that you should crossbreed them but GBA arent a separate species and it wont actually create hybrids like people think.

[Dixon1990]

That may have happened to the original ones taken, but that doesnt mean its happened to all taken from the wild.

And crossing them would stilll be making hybrids.

And it is wrong to breed them together.

And even if they were the same species, breeding them together wouldnt be the best idea as it would still be 'unpurifying' the strains.

[nemines]

Dixon, are you basically saying, (i'll use an analogy here) that it's wrong for a black man to marry an asian woman or an asian man to marry a black woman?

[Dixon1990]

No im not saying anything like that, im talking about FISH here not humans.

Other People are saying that soon it will be ALOT harder to import tropical fish, and crossbreeding isnt exactly going to help us keep different species/strains pure

[Cheesejawa]

I heard that most GBAs are decendants of the original wild GBA that was bred with the BN? Is it true that GBAs and just a variety of BNs that alos occours in the wild?

[Dixon1990]

Im pretty sure they are still taken from the wild, and still exist in the wild.

[SilverBlade86]

Hey, its really surprising when a topic you made 2 years ago comes back up.

Dixon, are you basically saying, (i'll use an analogy here) that it's wrong for a black man to marry an asian woman or an asian man to marry a black woman?

[David R]

Dixon, are you basically saying, (i'll use an analogy here) that it's wrong for a black man to marry an asian woman or an asian man to marry a black woman?

In a way, yes. At least if you are trying to keep the 'strains' pure. Obviously in humans this isn't a goal and so inter-race/strain marriages happen. Same with fish in the wild. Mr bristlenose is going to mate with any mrs bristlenose he can get his bristles onto, he's not going to worry about keeping the strains pure.

Breeding in captivity is a whole different story. Because you have removed the elements of natural selection/survival of the fittest, you must be careful to pick the best fish for your breeding stock. Also, you don't have geographic isolation keeping different varieties/subspecies separate (look at how many different frontosa there is from different type localities). So when selecting fish to breed you are essentially playing god/nature, and should put a little more thought into the fish you choose than the average joe who just goes to the nearest shop and buys a bunch of fish (which probably all came from the same supplier and even the same parents).