Ancistrus sp. Albino X Albino Equals what?

[rcbows]

If I breed One albino Male Ancistrus sp. with a Female albino Ancistrus sp. what should the results be?

[FishnFins]

Well in my experience depending on genetic history of the fish it could be anywhere from 50% albino all they way to 100% albino. The rest would be normal brown.

[rcbows]

Thats what I was wondering! I only always got 100% albino, but from this batch I got maybe 50% Albino & 50% Brown! Does anyone know why this is? Can you explain the genetics of it? I know that when I cross Brn X Brn and get 25% albino its because the recessive gene is in both parents. It produces 25% Albino & 75% Brn!

Ron

[dw1305]

Hi all,
You are right, something strange has happened.

Albinism is a recessive gene, so albino parents can only have albino fry. However I believe that there is more than one genotype of albino Common Bristlenose. I can't find the post but some-one "Mats P?" gave a pretty full explanation somewhere on the forum.

cheers Darrel

[rcbows]

I found the Post from MatP

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.
- Milton Tan
Biology Grad Student @ Auburn University

It doesn't really explain, everything about it! Anyone else got any Ideas?

Ron

[FishnFins]

Hi all,
You are right, something strange has happened.

Albinism is a recessive gene, so albino parents can only have albino fry. However I believe that there is more than one genotype of albino Common Bristlenose. I can't find the post but some-one "Mats P?" gave a pretty full explanation somewhere on the forum.

cheers Darrel

That would make sense to me, I bred a albino pair and only got about a 50 50 mix. When I put another different female I got all albinos.

[Narwhal72]

I had a pair of LF albino's that threw nothing but albino LF fry for a long time. Then one day they started to throw shortfin albino and then both shortfin and long fin brown fry.

There is more to it than simple Mendelian genetics. Age or environment may also contribute to the pigmentation/lack of pigmentation of the fish as well.

I no longer have the original pair but I do have some of the shortfin brown fry reared up and spawning (they have so far thrown nothing but shortfin browns) and some of the longfin albinos are spawning and have thrown a mix of shortfin and long fin albino fry (but no browns so far).


Andy

[rcbows]

Fin heredity is different than color genetics! The genetic mechanism is different!

Ron

[Narwhal72]

picky picky picky. I was just stating the facts of my own experience. The fin length may not be pertinent to the question of albinism but there was no harm in including it.

Here is the same post with the fin references removed.
I had a pair of albino's that threw nothing but albino fry for a long time. Then one day they started to throw both albino and brown fry.

There is more to it than simple Mendelian genetics. Age or environment may also contribute to the pigmentation/lack of pigmentation of the fish as well.

I no longer have the original pair but I do have some of the brown fry reared up and spawning (they have so far thrown nothing but browns) and some of the albinos are spawning and have thrown albino fry (but no browns so far).

That better Ron?

[rcbows]

Andy,
I wasn't trying to be picky! I was just making a point about Color Genetics! I wasn't trying to pick your post apart!

Ron

[Narwhal72]

No problem. Sometimes intentions are lost in text translation. No biggie.

[aquariumhobbyist]

I no longer have the original pair but I do have some of the brown fry reared up and spawning (they have so far thrown nothing but browns) and some of the albinos are spawning and have thrown albino fry (but no browns so far).

Could this be perhaps due to both albino parents in this case being albino due to these fish having the same gene resulting in albinism then?

[CoryfanAad]

I had a pair of LF albino's that threw nothing but albino LF fry for a long time. Then one day they started to throw shortfin albino and then both shortfin and long fin brown fry.

There is more to it than simple Mendelian genetics. Age or environment may also contribute to the pigmentation/lack of pigmentation of the fish as well.

I no longer have the original pair but I do have some of the shortfin brown fry reared up and spawning (they have so far thrown nothing but shortfin browns) and some of the longfin albinos are spawning and have thrown a mix of shortfin and long fin albino fry (but no browns so far).


Andy

Andy, to my knowledge two albinos (recessive gen) never can have brown fry. Also environment or age doesn't affect albinism to my believe. Could it be one of them being a leucistic one (no red eyes). In that case it could be. Regards Aad

[Narwhal72]

most likely. But the parents of these fish were also both red eye albinos and threw brown fry as they got older. It remains to be seen whether the process will repeat in this generation.


Aad-
both parents were red eyed albinos. and they definitely threw brown fry as they were alone in a 10 gallon tank so there were no other possibilities.

Environment can have an effect on sex ratios of fish (higher temperatures tend to produce more males) so it could also be possible that environment does affect gene expression. I only include age as a possible factor because it is something that started happening as the pair was approaching the end of their reproductive life. Damage to the gene as a result of age could have resulted in a different phenotypic expression.

Andy

[CoryfanAad]

most likely. But the parents of these fish were also both red eye albinos and threw brown fry as they got older. It remains to be seen whether the process will repeat in this generation.


Aad-
both parents were red eyed albinos. and they definitely threw brown fry as they were alone in a 10 gallon tank so there were no other possibilities.

Environment can have an effect on sex ratios of fish (higher temperatures tend to produce more males) so it could also be possible that environment does affect gene expression. I only include age as a possible factor because it is something that started happening as the pair was approaching the end of their reproductive life. Damage to the gene as a result of age could have resulted in a different phenotypic expression.

Andy

That's a miracle to me hahaha.

[Narwhal72]

Now I almost wish I kept more of those fry so I could do more experimenting.

Market for albino BN around here is saturated and they became so hard to sell that I got rid of my breeders and moved on to others. I kept a few fry in display tanks as algae control and they have started breeding but I don't think I have enough samples from the first generation to setup a test to see if I could repeat the process.

Andy

[aquariumhobbyist]

I had a pair of LF albino's that threw nothing but albino LF fry for a long time. Then one day they started to throw shortfin albino and then both shortfin and long fin brown fry.

There is more to it than simple Mendelian genetics. Age or environment may also contribute to the pigmentation/lack of pigmentation of the fish as well.

I no longer have the original pair but I do have some of the shortfin brown fry reared up and spawning (they have so far thrown nothing but shortfin browns) and some of the longfin albinos are spawning and have thrown a mix of shortfin and long fin albino fry (but no browns so far).


Andy

when referring to "brown" fry, are we referring to the standard BN pleco (which is usually referred to as black) or a new form which is brown?

[rcbows]

The original pair that I bred are albinos with pink (red) eyes! They bred together by accident and are throughing some albinos and some browns, about 50/50 ratio!

If you saw a solid black BN pleco you would say that the Common BN's are Brown not "Blacks"! I have a solid Black Pleco that I am line breeding to try to get a line of Solid Blacks. It may be a color phase of the Brown but it is definitely black.

If you bred a Blue Eyed Leucistic BN X with a Albino Pink Eyed BN, you should get all brown BN fry from that breeding. Shouldn't You?

Ron

[mattcham]

The answer to the OP's question has been known for decades. The reason is that bristle nose plecos have TWO different albino genes, both of which are recessive for albino. If your albino male and albino female happen to each be homozygous albino for different genes, then 100% of the offspring would actually be brown, even if both parents look albino white with red eyes. This has been known for a long time.

[Narwhal72]

when referring to "brown" fry, are we referring to the standard BN pleco (which is usually referred to as black) or a new form which is brown?

Standard BN pleco. In the U.S. they are commonly referred to as brown and not black.

Andy

[mattcham]

If you bred a Blue Eyed Leucistic BN X with a Albino Pink Eyed BN, you should get all brown BN fry from that breeding. Shouldn't You?
Ron

Correct. But this assumes that your breeding stock has that exact genotype. In reality it is possible that your blue eyed leucystic bn might be a carrier (heterozygous) for one or more albino red eyed genes.

[mattcham]

See here for info on the OP's first question:
http://www.angelsplus.com/FishBristlenoseAlbino.htm

Similar concept seen in guppies:
http://www.angelsplus.com/ArticleAlbino.htm

[mattcham]

Andy, to my knowledge two albinos (recessive gen) never can have brown fry.

That is incorrect. A red eyed white albino male and a red eyed white albino female may in fact produce 100% normal brown fry, if the two albinos are from different "clans", with each clan carrying an albino gene in a different location.

For simplicity sake, we can call them albino gene mutation 1 and albino gene mutation 2. Each fish needs two copies of either mutation 1 *or* two copies of mutation 2 in order to become white with red eyes. An albino male with 2 copies of mutation 1, when mated to an albino female with 2 copies of mutation 2, will produce 100% normal brown non albino fry.

There is no way to know from appearance whether a particular albino fish is carrying one or both mutations. This is why people are observing seemingly non-mendelian results when in fact the genetics are 100% Mendelian.

[CoryfanAad]

Andy, to my knowledge two albinos (recessive gen) never can have brown fry.

That is incorrect. A red eyed white albino male and a red eyed white albino female may in fact produce 100% normal brown fry, if the two albinos are from different "clans", with each clan carrying an albino gene in a different location.

For simplicity sake, we can call them albino gene mutation 1 and albino gene mutation 2. Each fish needs two copies of either mutation 1 *or* two copies of mutation 2 in order to become white with red eyes. An albino male with 2 copies of mutation 1, when mated to an albino female with 2 copies of mutation 2, will produce 100% normal brown non albino fry.

There is no way to know from appearance whether a particular albino fish is carrying one or both mutations. This is why people are observing seemingly non-mendelian results when in fact the genetics are 100% Mendelian.

Thanks for this great info. Learning quite interesting stuff every day!! There seem to be different albino appearances as well (whitish red eyes and yellow with red eyes). Does that have anything to do with the mentioned different mutations ??? Do this count for other fish (Corys for instance) as well? Regards Aad

[mattcham]

There are at least two albino BN genes, both of which have yellow bodies. I do not know if there is a third albino gene with snow white body and pink eyes. There is definitely another mutation with yellow body and black eyes.

All the red eyed snow white bodies I have purchased from 6 sources turned yellow after they settled in my tank. None of them stayed snow white for more than a month. I am convinced that real snow white BN do not exist but I may be wrong. I have never seen an owner showing both types side by side. Just one or the other. I bought those white ones but they turned yellow.

It is possible that a fish is homozygous for TWO of the albino mutations. I wonder if such fish would be snow white.

My albino Cory are all pinkish snow white. I have albino aneus (bronze) and albino plateus (peppered).

I also have albino molly. Snow white at pet store. Dominant female turned yellow after 3 months of ownership. When I moved the dominant female permanently to a separate tank, a new dominant snow white female in the old tank turned yellow within a week.

[rcbows]

Can anyone show what the Punnett square for the breeding of albino 1 X albino 2 that produce 1/2 brown offspring would look like?

Ron

[mattcham]

Here you go -Two albino parents producing only 50% albino fry:

aaBb x AAbb =
50% AaBb (brown phenotype)
50% Aabb (albino phenotype)

Legend:
aaBB= homozygous for albino 1
AAbb= homozygous for albino 2
aaBb= homozygous for albino 1 AND heterozygous carrier for albino 2
AaBb= heterozygous for albino 1 AND heterozygous for albino 2
Aabb= heterozygous for albino 1 AND homozygous for albino 2
AABB= wildtype

Simple!

[bekateen]

There are several websites with Punnett Square calculators that you can use to play with different genetic combinations to figure out the % of each phenotype. One such site is http://scienceprimer.com/punnett-square-calculator.

Cheers, Eric

[rcbows]

Thank You Mattcham & Eric, you both helped a lot!

Ron

[bekateen]

It is possible that a fish is homozygous for TWO of the albino mutations. I wonder if such fish would be snow white.

If the parents you have really do possess albino mutations at different genes and were thus able to produce 50% brown, 50% albino F1* hybrid offspring (as predicted by the above posts and the Punnett square), then you can test your hypothesis about a double recessive being able to produce the "Snow White" phenotype using the albino F1 offspring you're raising:

The genetics shown above predict that all of your albino F1 fry will be homozygous recessive for one gene and heterozygous for the other, although we wouldn't be able to tell which gene was homozygous and which was heterozygous.

If you cross these albino offspring exclusively with each other, then you will get the following results:

All of the F2 will be albino, but 75% would be albino due to only one gene defect and 25% would be homozygous double mutants - if this creates the Snow White phenotype, then you will get 25% Snow Whites! On the other hand, if the Snow White phenotype is caused by a different genetic defect, OR if the Snow White phenotype isn't actually a heritable trait but is just a temporary phenomenon associated with aging or housing conditions, then you will get 100% typical yellow albinos.

*Note: I am using F1 to refer to the offspring from your original cross; I'm not using it in reference to the offspring of wild caught fish.