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The most recent spawn of my albino bristlenoses produced a bunch of brown babies. To my knowledge, the last spawn from this mother and father were all albino. How does this happen? I have raised the water temp since the first time they spawned from 75 to 78, but everything else is the same. I was under the impression that albinism is a recessive gene and albino parents would only produce brown young if they were of different species.

I have three females and all have produced 100% albino young in the past. Any ideas why the babies are brown now? They are active and healthy otherwise. Thanks!!!!


Andy

One of the parents must not carry 2 albino genes. If they each pass on 2 genes one must be a/b and the other a/a. Your ratio should be more like 1/2 brown. Albino is a recessive gene so unless you get an a/a combo they will be brown.
If you still have the females tht produced all albino fry, put the current breeding male with one and see if the fry are all albinos. If they are you know the female carries the gene.

I imagine that it must be in the female, since there are 3 females and one male. But, wouldn't an a/b be a brown fish? I thought that if there were any brown genes in a fish that it would be brown, because of the recessive trait.

The brown babies are much larger than the siblings from the same spawn. Is that normal?

If one brown parent had 1 gene for brown and 1 gene for albino, that fish would be brown. However, if the other parent has 2 albino genes, half of the fry will be brown. It can get pretty confusing but using a Punnett Square makes it much easier. You can find simple instructions at http://www.borg.com/~lubehawk/psquare.htm on how to use a Punnett Square. Hope it helps.

What drgold is saying, I think, is that his two albino parents have created some brown fry. I am understanding that there are no brown adults in the tank.

No clue why you are getting brown fry... you should not be based upon genetic probability. Maybe a mutation, but you would probably not see more than one brown fry if it were a mutation.

exactly...there are 4 albino adults in the tank, and no brown fish except the fry.

There are at least 8 brown fry, maybe more. There are over 100 albino fry in the tank, from 4 different spawns. The browns all came from the most recent spawn, on 11-23.

Truly weird.

Did you have fry die off very young in the other spawns, or maybe the particular female who had the brown fry didn't spawn before.

A friend of mine has an albino pair, but they have 1/2 brown fry. Brown BN fry start out looking like albinos with no colour, then darken by the time the egg sac has been absorbed, so if you had some die off they may have been brown ones.

I only had one fry die so far, and it was albino. I'm almost certain that this mother has spawned for me before and the last batch were all albino. The father has been the same for all babies. I think I'll contact the breeder and see if this has happened to him. That should answer some questions.

Hello,

I am not a very experienced catfish breeder, but I do have a fair amount of experience in breeding budgerigars (cfr. my nickname). There are 3 possibilities that I can think of that would result in brown fry from albino parents. The first one could be the case when the albino trait in one of your parent fish is a dominant trait and that parent only carries one dominant albino gene. About half of the fry should be (visible) brown then. But I believe that a dominant albino gene is very in the animal world...
Another possibility is when the (both) albino genes of the mother are sex-chromosome-linked recessive, and the albino genes of the father are autosomal recessive genes. This means two visible albino parents, but genetically carrying different genes that result in an albino appearance. This pairing could theoretically result in brown fry. About half of the fry in the batch should be brown then though. In budgerigars there exist a few mutations which are phenotypically identical but which are caused by different genes.
A third possible explanation is the fact that the albino appearance is caused by two linked genes (which are lying on the same chromosome) that "work together" to create a visible albino, if a crossing over occurs, the fry only inherit one of the two necessary genes and thus are visible brown. This last explanation could explain the fact that a strange (not mendelian distributed) percentage of the fry is brown.
Barbie: I know of the practice in birds (which in my opinion is totally not acceptable) to breed-in mutations in related species. The breeder takes a mutated bird of one species ( a species where the mutation is already common) and crosses this bird with a regular colored bird of the other species where the mutation does not exist yet. The offspring is then crossed back to the species where the breeder wants to introduce the mutation. In this way, they "create" a mutation in the other species, but of course the birds will be NEVER really the original species. So I doubt that crossing albino specimen of different ancistrus species would result in brown fry. In my opinion you get a cross of the two species, but still albino. Unless the traits that cause albino appearance inherits differently. But this will repeat the story...

I hope I didn't type too much mistakes, since I rather typed this text in a hurry...

Regards,
Wim

Barbie (and al others): it was never my intention to make any insinuations. I just wanted to tell the people about a practice that was (and still is) used in birds.

Regards,
Wim

Till more is know about the genetics of BN we won't be sure. With angels it is possible to get "throw backs" from grand parents. This is from breeders who have kept track of the genetics of fish they have bred and kept to use as breeders. There are not very many...ie 1 or 2 in a spawn of say 400, but it does happen. That doesn't follow the rules of angel genetics and much more is know about them than plecos right now.

The more information we have the better. Most of us don't know the genetics of our plecos unless we purchase them from a breeder and find out.

I do know my long finned albino BN are from a pair that are both lfa and they only throw lfa. Mine have yet to spawn, but I will have to assume that is all they will throw as well.

My common brown ones....sold as gold spotted BN only have brown. I still have yet to determine the exact name for them as they look like A. Temminicki, but have been told it is unlikely they are.

The breeder told me that his original pair was made of two brown fish. He said that he only kept the albino babies from that pair and then continued on to only breed albinos.

So...I am likely seeing the vestiges of the brown grandparents here, like what was said above of the angelfish.

It should be impossible for 2 albino fish to throw a colored fry, if they are the same species.

hence my confusion.....

I found another couple of browns, bringing the total to 7. they were hanging in the cave with Dad. Assuming a few unfertilized eggs were eaten, 7 fish may be about 1/4 of the fish from that brood.

The fish should be big enough to photograph in a week or so.

My smallest female (2.75") just dropped her second batch of eggs yesterday, so hopefully no surprises from her. The browns are from my medium female (3") who has previously produced all albinos.

I won't sell the browns to anyone, to prevent any distribution of weird genes. I'll probably keep them around for general algae-patrol, or give them to friends who aren't breeders. No worries. This is fun, though, isn't it?

Could it be that the brown is just baby colors? Maybe it is temporary.

This is not the first time I have seen this question asked.

Another aquarist (a well know Angelfish breeder) had been experiencing the same issues with his line of albino Ancistrus.
When young, his group would produce abino offspring, now that they are older, he told me they are producing more and more normally colored fry.

It would depend on the nature of the mutation that leads to albinism in these fish in the first place but there are a number of things that could be at work here (or interactions therein):

1. Environmentally influnced phenotype (or age influenced, etc).
Half-black angelfish are a good example of this. I don't believe science has arrived at a complete explaination for this one yet.

2. Non-medelian genetics: Multiple allels could be involved to produce pigments each with it's own mechanisms of expression(linked, dominant, recessive, co-dominant, etc., etc.) A mutation in any one of them could result in expression of pigments.

3. It could all also be a function of a non-coding RNA (ncRNA, a relatively new discovery in molecular biology). These have been discovered to act as regulatory RNA molecules in cells. One of the first of these was discovered in that it can stop the hyperexpression of a virus genotype (very useful in avoiding virus' from taking over the mechanisms of a cell) by reading and destroying virus encoding tRNA. These could be at work in expression in either the offspring or in the parents meiotic cells.

The problem is that one would need a very well equiped molecular biology lab just to test these hypothesis' above. (And likely a PHD in molecular biology to boot!)

As frustrating as it may be I doubt you'll find your answer on these forums but you are certainly not alone in your experiences.

I'm writing to confirm to DrGold that I have observed the same phenomenon in my Albino Ancistris. That is: a pair of Albino Ancistris that were producing all albino offspring brood after brood, stopped producing albinos and now only produce browns.

This has nothing to do with Mendel's law. My guess is that this is due to an environmental factor affecting parents or eggs or developing embryos. This can't be a mutation because as someone pointed out in an earlier post, a mutation would only be seen in a single offspring. The genetic switch for melanin production is somehow getting turned on in all of the offspring at once. Its quite amazing.

Question: can the melanin switch get turned back off again or is the effect irreversible?

Another question: will the brown offspring (F1) produce brown or albino offspring (F2)?

If I found out any answers I'll report back to this thread.

DrGold, Thanks for posting this (and thanks to a good friend for telling me about your post). I was happy to find someone else who observed the same thing.

Is it possible that this is an 'incomplete' Albinism in these fish rather tha a 'true' albinism as albino ancistrus are a yellow colour, sometimes with light grey traces on fins rather than the white/pink of a true albino?. I know the gene is the main one that shows up with albino guppys allowing them to be albino with coloured markings. Do the eyes still show up a deep ruby colour on the brown fish or like that of a normal fish?

I think they have normal, black eyes. They're small and hard to see, though. But yeah, black eyes.

I was also wondering if anyone knows or could point me in the direction of some genetics theory regarding true albinism Vs Incomplete albinism. Before breeding fish I was breeding Fancy pet rats for a very long time (7 years) And while the true albino animals held to the reccessive gene theory the Incomplete albino animals threw the theory out the window. They had a Fatal/deforming mutation that would occour if you bred albino/albino so one parent would have to be a non albino. They always produced around 25% albino, 25% non albino and a very strange third group I called 'dark albino'These were darker than the albino parent, fur sometimes the full colour of the dark parent but had deep red eyes. Knowing almost nothing of genetics at the time I thought this was normal. But reading the above topic it seems impossible. Might not have much to do with fish but I know this 'incomplete' trait occours in some fish species.

Edit: was directed to this site about human albinism that has a few interesting effects of 'incomplete' albinism and how the production of melanin was sometimes just 'leaky' and even repaired with age, might be worth a read and shed a little more light. http://albinism.med.umn.edu/facts.htm#class

Azmeaiel wrote:Is it possible that this is an 'incomplete' Albinism in these fish rather tha a 'true' albinism as albino ancistrus are a yellow colour, sometimes with light grey traces on fins rather than the white/pink of a true albino?. I know the gene is the main one that shows up with albino guppys allowing them to be albino with coloured markings. Do the eyes still show up a deep ruby colour on the brown fish or like that of a normal fish?

That was what I was thinking... but didnt want to say since I know little about fish genetics