Ancistrus sp. Albino X Albino Equals what?

[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.

[rcbows]

Just to clarify things I was talking about breeding a true Albino w/ Pink Eyes to another true Albino w/ Pink Eyes, they produced half brown and half albino off spring. They are small right now about 1/2" so I can't see eye color on the young fry, and the browns are a beige shade not dark like other Brown Bn's, but they are half and half. Thanks

Ron

[mattcham]

Just to clarify things I was talking about breeding a true Albino w/ Pink Eyes to another true Albino w/ Pink Eyes, they produced half brown and half albino off spring.

Yup. And the punnet squares we made are also for that situation.

we wouldn't be able to tell which gene was homozygous and which was heterozygous.

Therein lies the biggest problem. We'd have to setup 10 or more breeding tanks to get a decent chance at producing aabb fry. If all the 500 fry end up being golden yellow rather than white, is it because aabb genotype has a golden yellow phenotype? Or maybe none of the 500 fry are aabb genotype due to randomly wrong pairings? No way to know, and what a headache that would be...

[bekateen]

we wouldn't be able to tell which gene was homozygous and which was heterozygous.

Therein lies the biggest problem. We'd have to setup 10 or more breeding tanks to get a decent chance at producing aabb fry. If all the 500 fry end up being golden yellow rather than white, is it because aabb genotype has a golden yellow phenotype? Or maybe none of the 500 fry are aabb genotype due to randomly wrong pairings? No way to know, and what a headache that would be...

No, that shouldn't be necessary. From the original Punnett square where two albinos (again, assuming only two genes are involved, both with recessive alleles for albinism) were crossed and we obtained 50% brown, 50% albino F1, it is evident that all of the albino F1 are of a single genotype, either aaBb or Aabb, but definitely not a mix of these two.

If you are crossing F1 that are all aaBb x aaBb (or Aabb x Aabb) then as the second Punnett square shows, statistically speaking you should get about 25% aabb, no matter which of the two parental genotypes you start with. So if you obtained 500 fry from this crossing, the odds that none of them would end up double homozygous recessive are extremely low, unless being double recessive conveys some kind of disproportionate mortality.

You mentioned 500 fry. Is that how many you'd expect to get from 10 crossings? (I don't know the avg clutch size of bristle noses). Even in a single clutch of eggs you would expect to get 25% aabb, so you should be able to test this in only one or a couple of pairings.

[aquariumhobbyist]

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.

What are the differentiating characteristics of these two albino BN genes, both of which have yellow bodies?

When you refer the "another mutation with yellow body and black eyes" I assume you are talking about the one that is commonly referred to as the L144 (sp(4) on the database)?

Someone on the forum was insisting there were two forms of the false L144; one with black eyes and the other with blue eyes... I am not sure such a distinction exists but the fish owner said his fish had blue eyes...

[aquariumhobbyist]

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

here is a post from someone here on the site... perhaps this could answer your questions?

Hi,

well, I am not a biologist, so perhaps a geneticist can better explain (or perhaps even explain why my explanation is wrong).
And after looking it up again, I realize that the english word is actually xanthism..

Those are different kinds of mutations: leucistic individuals do not have melanocytes at all (and thus tend to be white), while xanthistic individuals lack in melanine production, while the xanthophores (producing ceratines) are still functioning at normal levels, thus making the individual yellowish (even reddish; see the "Super-Red" variety).

Thus, a leucistic form should actually be white (see Astyanax jordani for example), while xanthistic forms are yellow.
So from that I do not believe that the black eyed varieties are leucistic, they probably are xanthistic as well (but perhaps with a different form of genetic defect).


With respect to eye colors: I wasn´t suggesting that it is only light that causes blue eyes, and you are right, there indeed are black as well as blue eyes in different forms. What I was hinting at is the fact that a fish with black eyes can appear to have blue eyes in a picture under certain lighting conditions (this is probably not general: not every fish will have blue eyes on pictures under certain conditions).
This means (and this is the most important point I was trying to make with it) that just because a fish has blue eyes on a picture does not automatically mean that it absolutely needs to have blue eyes in real life to fit the bill.

Cheers,
Sandor

edit: you can read the whole thread here: http://www.planetcatfish.com/forum/view ... =5&t=41052

[rcbows]

I have (3) Leucistic BN's and all three have blue eyes. I have never heard of a Black eyed Leucistic BN until just now in this post! Although I never heard of Two Albino Genes in any other species either, are you sure there is such a thing?

Ron

[rcbows]

In you reference post, viewtopic.php?f=5&t=41052 you mentioned xanthoristic variant, I tried looking it up under Wikipedia and there was no such word, What doe sit mean?

Well, in this case even that won´t help, because there appear to be no real L144 available anymore (there might be one or two hobbyists remaining that still have them, but basically all Germans have the xanthoristic variant of the common bristlenose by now, and we have come to call them Ancistrus sp. "Yellow-Black Eye"). They are being sold as L144 everywhere.

Ron

[rcbows]

I found "Xanthism" in the glossary (I forgot it was there) but not used as you are using it. Now my next question, are you calling a leucistic BN considered to be as one of the albino genes or are there (3) genes in BN' that cause lack of pigmentation regardless of the eye color or only two (Albino & Leucistic)? Very...

Ron

[rcbows]

Next Question (I have lots of questions) is a Super REd BN a Xanthochromic individual genetically, or something else!

Ron

[mdcham]

we wouldn't be able to tell which gene was homozygous and which was heterozygous.

Therein lies the biggest problem. We'd have to setup 10 or more breeding tanks to get a decent chance at producing aabb fry. If all the 500 fry end up being golden yellow rather than white, is it because aabb genotype has a golden yellow phenotype? Or maybe none of the 500 fry are aabb genotype due to randomly wrong pairings? No way to know, and what a headache that would be...

No, that shouldn't be necessary. From the original Punnett square where two albinos (again, assuming only two genes are involved, both with recessive alleles for albinism) were crossed and we obtained 50% brown, 50% albino F1, it is evident that all of the albino F1 are of a single genotype, either aaBb or Aabb, but definitely not a mix of these two.

If you are crossing F1 that are all aaBb x aaBb (or Aabb x Aabb) then as the second Punnett square shows, statistically speaking you should get about 25% aabb, no matter which of the two parental genotypes you start with. So if you obtained 500 fry from this crossing, the odds that none of them would end up double homozygous recessive are extremely low, unless being double recessive conveys some kind of disproportionate mortality.

You mentioned 500 fry. Is that how many you'd expect to get from 10 crossings? (I don't know the avg clutch size of bristle noses). Even in a single clutch of eggs you would expect to get 25% aabb, so you should be able to test this in only one or a couple of pairings.

I agree. You are correct!

[mdcham]

What are the differentiating characteristics of these two albino BN genes, both of which have yellow bodies?

As far as I know they look totally identical.

[mdcham]

When you refer the "another mutation with yellow body and black eyes" I assume you are talking about the one that is commonly referred to as the L144 (sp(4) on the database)?

Someone on the forum was insisting there were two forms of the false L144; one with black eyes and the other with blue eyes... I am not sure such a distinction exists but the fish owner said his fish had blue eyes...

I have been following the L144 auctions at AquaBid.com for the past year and it seems to me that there are more than 5 varieties of white (or yellow) bodied BN with blue (or black) eyes. Their body shapes are so different from one another unrelated to long fin versus short fin. For example, some have white spots on their bodies and some do not. Some long finned have super long fins while others have basic long fins. Its hard to tell whether eyes are really black or blue because this can be affected by lighting and photography. When it comes to L144, its very complicated due to too much hybridization I think.

[mdcham]

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

here is a post from someone here on the site... perhaps this could answer your questions?

Hi,

well, I am not a biologist, so perhaps a geneticist can better explain (or perhaps even explain why my explanation is wrong).
And after looking it up again, I realize that the english word is actually xanthism..

Those are different kinds of mutations: leucistic individuals do not have melanocytes at all (and thus tend to be white), while xanthistic individuals lack in melanine production, while the xanthophores (producing ceratines) are still functioning at normal levels, thus making the individual yellowish (even reddish; see the "Super-Red" variety).

Thus, a leucistic form should actually be white (see Astyanax jordani for example), while xanthistic forms are yellow.
So from that I do not believe that the black eyed varieties are leucistic, they probably are xanthistic as well (but perhaps with a different form of genetic defect).


With respect to eye colors: I wasn´t suggesting that it is only light that causes blue eyes, and you are right, there indeed are black as well as blue eyes in different forms. What I was hinting at is the fact that a fish with black eyes can appear to have blue eyes in a picture under certain lighting conditions (this is probably not general: not every fish will have blue eyes on pictures under certain conditions).
This means (and this is the most important point I was trying to make with it) that just because a fish has blue eyes on a picture does not automatically mean that it absolutely needs to have blue eyes in real life to fit the bill.

Cheers,
Sandor

edit: you can read the whole thread here: http://www.planetcatfish.com/forum/view ... =5&t=41052

I am in complete agreement with that post. He gives the textual definitions of each phenotype but it does not answer the question of whether aabb genotype will look like a snow white pleco. All the snow white pleco I bought eventually became gold yellow. But that's just my experience and others may disagree.

I have never seen an owner who owns both snow white and also yellow gold pleco. Yellow pleco can become snow white if they are frightened, stressed, or sick.

[mdcham]

I have (3) Leucistic BN's and all three have blue eyes. I have never heard of a Black eyed Leucistic BN until just now in this post! Although I never heard of Two Albino Genes in any other species either, are you sure there is such a thing?

Ron

Look at my prior posts in this thread. This is a fact that has been known for decades in BN pleco world. It is also seen in guppies. See my prior posts.

[mdcham]

In you reference post, viewtopic.php?f=5&t=41052 you mentioned xanthoristic variant, I tried looking it up under Wikipedia and there was no such word, What doe sit mean?

Well, in this case even that won´t help, because there appear to be no real L144 available anymore (there might be one or two hobbyists remaining that still have them, but basically all Germans have the xanthoristic variant of the common bristlenose by now, and we have come to call them Ancistrus sp. "Yellow-Black Eye"). They are being sold as L144 everywhere.

Ron

The term to look up is xanthic. It is just a scientific word for yellowish, meaning the fish lost all pigments except for yellow. Even though the word sounds exotic, it is really just the same as calling something yellow. This refers to the appearance, not a particular gene, and is not any more meaningful than just calling something yellow. You can use it to sound like a professor ha ha. This xanthic appearance is seen in other fish like tiger barbs and guppies, also seen in birds, reptiles, AND humans!!!

In the bristle nosed world, there are at least 2 different xanthic mutations.

[bekateen]

Funny thing about our noses (no pun intended, even though this thread is about bristlenoses): Something can be right under our nose, and we still can't see it!

In this thread, there was all this talk about white albino bristlenoses; and when I typed my posts in this thread I wondered what these "white" albinos looked like. I've had ABNs for almost a year now, two females and a recently added male (and more recently a bunch of babies). Then just today it struck me that one of my females is a white morph (or so I presume):

Last Spring, I bought both females (as unsexable juveniles) from different stores; one was the typical yellow color and the other was simply "pale" in comparison. At the time, I didn't think anything of the color difference, because based on what I'd read in other threads, I expected the pale female to "outgrow" that color and turn yellow. Both females were virtually the same size (about 1/2 to 3/4 inch SL) at the time of purchase.

Fast forward almost a year, and the pale female is still is pale: In fact, now she is almost a snow white color compared to the yellow female and compared my male, who is also yellow (see photo). And it's not as if my white female changes from white to yellow and back again - she's always white. Sometimes, when she is stressed, she turns almost pink as she vasodilates and blood flows more heavily near the skin.

Another odd difference: The white female is now less than half as large as the yellow female (the yellow female is about 4 inches SL). Since these females were store bought, I don't know their specific ancestries. But I do know that I bought them from different stores in different cities, and that their genetic ancestries are different. It's possible that my white female is just a lone genetic "runt of the litter;" but I'm also wondering if white ABNs (as a group) are genetically smaller than yellow ABNs (as a group). I am confident that the difference between my two females is NOT the result of one hogging food or socially dominating the other, because I raised each female in separate, virtually identical tanks (each female was raised in a separate 10gal tank used for growing out cory fry, and each tank was maintained in an identical manner; it was only recently, when I purchased the male, that I put the two females into the same tank, to give the male a choice of mates).

Does anybody know if yellow ABNs, as a group, grow larger than white ABNs? Or has anyone grown out white ABNs to the "normal" full size of other ABNs? Does anyone have any experience with both color forms to have an informed opinion about this? Thanks.

Cheers, Eric

EDIT: I changed my description of the white female from "ghost white" to "snow white," because who knows if ghosts are really white, right?!? But clean snow does look white like this fish (I know, there is yellow snow too, but that's something completely different. LOL)

[mattcham]

Thanks for sharing this Eric. It's really interesting that your white albino has stayed white. All my white albinos eventually became yellow albino. You should try to selectively breed that white one. Try to find a white male from the same fish store so that the genetics will not be contaminated. If the fish store no longer sells them, perhaps ask where they sourced it. I have not seen any pleco breeder/seller on Aquabid who maintains separate strains of white and yellow albinos. If your white albino is really genetic (as opposed to a stressed or ill fish), I would say that it is much much rarer than the yellow albino version. I would definitely be interested in purchasing these myself if I knew where to find them.

[bekateen]

Thanks mattcham. As for source, I'm not 100% sure, but I believe the white fish was from either Petco or Petsmart. When I was buying these, they were so small at these stores; I think I bought 5 or 6 total from these sources, and this white fish was the only one to survive (I didn't buy them all at once: I'd buy 3 and two would die, so I returned them under guarantee and get replacements, and so on). The yellow female, and later the yellow male, are both from a small LFS in Modesto California. The female was also small when I got her but she grew vigorously; the male was purchased as young adult.

If you notice in one photo, there are fry in the tank (about 18mm long). But I don't know which female is the mom. I suspect it's the yellow female. I definitely will try to breed the white female. I'll have to cross some male F1s back with her to try and get a white F2. Theoretically that should produce a pure line, IF this white condition is a simple recessive genotype.

That said, I must admit I'm not a big fan of line breeding new mutants; but I also can't be hypocritical, since I DID buy ABNs and I DID intentionally breed them, and even the typical yellow ABNs are line bred mutants. But I'm a little more concerned in this case, given the high mortality of my initial purchases (which could be due to their genetics, but it's more likely just because they were from a chain store, or it could have been my fault since these were my first BNs ever), and also given the slow growth of this female (that's why I'm seeking other people's experiences with white ABNs). If I do succeed and get pure breeding whites, I'd be very alert for and concerned about the presence of any obvious physical deformities, like bad spines, eyes, fins, etc. And if that occurred a lot, then I'd shut the line down.

I do agree that a white ABN is pretty rare, at least where I live. But if it was from Petco or Petsmart, I would expect that there are more around, just because of the sheer number of fish sold in these stores. Either way, I'm happy to have it, and I hope I get some healthy white babies.

Thanks again, Eric

[bekateen]

my white albinos eventually became yellow albino

At what size and age did your white albinos turn yellow?

[mattcham]

My white albinos turned yellow very early, at around 2 inches in length (including tail). Sometimes they go back to being white when they get scared. For example, when catching them or removing their caves for cleaning. Petsmart and Petco source their fish from a California importer. I'm guessing those fish are shipped from Southeast Asia where there are tons of tropical fish farms. The wild fish that are difficult to breed in captivity are imported mainly from South America. I did notice that the albino plecos at my local Petco are snow white, but I thought they were just scared or sick.

If your white albino and yellow albino are homozygous for albinism on completely different genes, then 100% of their offspring SHOULD be brown. If their offspring are not 100% brown, it means that one of them is a carrier (heterozygous) for either yellow or white while being homozygous for yellow (or white).

Maybe I'll go back to checking Aquabid regularly to see if anyone has snow white long fin albinos (I've never seen them) to add to my collection.