Breeding Albino Ancistrus cf. cirrhosus

[navyscuba]

So this is my first time breeding this species but I had breed whiptail catfish in the past but something that is getting me off guard is that I have this spawn of a pair of Albino Ancistrus and the fry were yellowish for the first few days and they all turn like brownish. Why is this happening if the parents are both albino? Will they change back to albino or they will just carry the gene? <edit: removed request for emails --Mats>
Thanks.

[MatsP]

There are, as far as I understand, at least two different kinds of albino. The production of brown body colour is quite a complicated process, and if the "right" steps are broken, it becomes "no brown colour".

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Mats

[navyscuba]

I don't get what what you are trying to say Matsp. I know they are Blue eyed Ancistrus and the normal Red eyed. Mine are Red Eyed.

[Suckermouth]

Eh, that's not what Mats is saying, but I can see your confusion. He's saying that there are multiple different "types" of normal red-eye albinism, even ignoring the blue-eye types.

Albinism is defined as the lack or or defective production of melanin, which is responsible for brown pigment. Multiple genes contribute to the production of melanin. It turns out that if you mess with any one of those genes you can get an albino fish. The hypothetical situation Mats is suggesting is that the female albino fish has something wrong in one gene, while the male albino fish has something wrong in another gene. They will both be albino but for different reasons. What this means is that any fry that the pair will have will get the defective copy from one parent, but a working copy from the other parent for both genes. The working copy is going to be dominant over the recessive albino allele, and therefore the fry will appear perfectly normal.

I find it fairly unlikely that you just happened to get one of one type and one of the other, as I'd guess that there's a "usual" gene that is defective in most albino Ancistrus. Furthermore, albino Ancistrus from the same source are likely going to be siblings or close relatives; thus, they would be albino due to a defect in the same gene, as opposed to different genes. However, you can't argue with the evidence of you having non-albino fry...

You mention that the fry were yellow at first; was this before they absorbed their yolk sacs? Loricariid fry typically don't have their color fully developed yet while they are still yolk-sac larvae, although the default color is more white-ish IMO rather than yellow.

[navyscuba]

Yes. They were pink/yellow when they hatched and were still feeding on their yolk sac. They were from the same source at the same time, so probably from the same spawn. We were just line breeding to get a first spawn, but now we are very confused. It's highly unlikely that two fish from the same spawn would have different defective genes effectively making their phenotype albino so that again leaves me confused. I can definitely see how two different fish from different stock could be amelanin by different genes... I had forgot to think about different genes rather than just alleles... but that takes me back to wondering how in the world we got brown or calico... Hmmm. At least that means that if we breed this stock back together we should get 25% albino... Very interesting to think about.

[Suckermouth]

It's highly unlikely that two fish from the same spawn would have different defective genes effectively making their phenotype albino so that again leaves me confused.

Agreed, but I don't really know any other explanations for getting non-albino fry from albino parents, besides even more unlikely scenarios such as mutation back to wild type or something.

At least that means that if we breed this stock back together we should get 25% albino... Very interesting to think about.

Not quite. In our hypothesis is correct and the genes are not linked, you will get a 9:7 ratio of brown to albino. This is a variation of the dihybrid cross where you expect a 9:3:3:1 ratio, but homozygosity of the recessive allele in either of the genes leads to albinism).

[Narwhal72]

I have a pair of brown longfin bristlenose that throw albino, brown, shortfin, and long fin fry. Breeding the albino fry back to each other produces a greater amount of albino but also the occasional number of brown fry as well.

Andy

[Suckermouth]

I have a pair of brown longfin bristlenose that throw albino, brown, shortfin, and long fin fry. Breeding the albino fry back to each other produces a greater amount of albino but also the occasional number of brown fry as well.

Andy

Hmmm, perhaps albinism is not as simple as assumed in Ancistrus for some weird reason. That's really odd.

[MatsP]

Thanks Milton for explaining things - yes, that's what I meant.

Is it possible that the fish came from the same tank, but from different parents? I agree it's unlikely...

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Mats