albino genetics or why 2 yellow fish throw normal brown

I am seeing this all the time, somebody gets 2 yellow BN, they spawn and all or some of the fry are normal browns and puzzlement abounds. The most commonly given explanation is that there must have been some normal browns fairly close in the pedigrees of one or both parents. For that explanation to be true, albino would have to be a dominant or partially dominant gene and in most cases I don't believe that is so.

All yellow BN are not genetically the same, nor are all yellow BN albinos. The L-144 is a yellow BN but not albino. There are known to be at least two genetically separate types of true albino in the common BN. If you breed the different genetic types of albino together, the result will be normal brown fry and this is far and away the most common reason two albino BN throw normal brown fry.

Albino is a simple recessive in most living things, and it appears that this is the case with the two commonly known types of albino BN.

Albino animals cannot produce dark pigments. The production of dark pigment is a multi step process so a gene that codes for a disruption at any of the steps will break the chain of pigment production and cause an albino. A gene that disrupts the first step and a gene that disrupts the last step will both cause true albinos, but the genes are not the same, they are genetically separate defects that both happen to result in an albino, this is how it is with albino BN
Any albino X L144= normal brown. Albino X golden albino=normal brown. All this is true at least 90+% of the time.

The biggest difficulty is in determining just what kind of yellow BN you have. It's fairly easy to tell the L-144 from an albino, look at the eyes, if they eyes are black or blue, it's an L-144, if the eyes are red, it's an albino.

According to Ingo Seidel, one type of albino has a rich yellow color and does not show any patterning, the other type is lighter in color and does show a pattern of spots.

Unfortunately color in fish is not determined by straight genetics, mood, diet and other external factors all play a part in what you visually see. This being the case, determining what type of albino you have by simply looking at it might be easier said than done.

My golden albinos do not show any spotting as per Ingo's description. However I have had correspondence with others who do have golden albinos that do show spotting. I don't know if this is visual overlapping of the two types or yet a 3rd type of albino.

I have also seen an occasional (2) light brown BN. One of these fish was known to have an albino parent and the other was suspected to. This could be a rarely occurring semi dominant albino or a combination of other factors working on a heterozygous condition of one of the regular albinos. I do not know.

Clearly all the facts regarding albino genetics in the BN are not yet known, but 90% of the time or better the reason two albinos produce normal brown fry is because the albino parents were not the same genetic type of albino.

Regards
Amber

ive kept both the sp1 and sp2 albino this worked out well as i could split the sexes from both types.
and every now and again they would spawn in the grow out tank and i would find some fry in the tank. but their was never any brown?? and the fry were dissposed ov
the only time i ever got any brown young is when i bought a 4" female from a lfs and added it to my group and i got about 10% browns so she went back to the shop and ive never had any more browns from the group.

Your experience does seem to be one of the exceptions to the opposite type of albino makes brown theory. I can think of a way that both could be true, but I don't know how likely it would be and it would only be speculation anyway; impossible to ever prove without that lfs albino female.
All my BN have been very predictable in what colors they have and have not thrown so far so if anybody in the Western US has any of these albinos that throw browns when bred to their seemingly same type, let me know. I'll do some test breedings and see if it sheds any more light on the puzzle.

My golden does have red eyes. The female he has spawned with is a common brown. The fry I have seen in the tank range from brown to golden to one solid white.

Thank you very much for the info!!

yea its not fair when u dont know ur fishs background. my calico male and albino only have common fry

This does not suprise me as you say Albino is a recessive gene
I have a breeding group of commons. First batch all brown commons, 2nd batch 20% albino's.
I know someone what has bred longfins with all common fry.

I am not into genetics but from what I know only a percentage of the genes are transferred to offspring. Thus is makes common sense to me that albinos could in theory produce all browns

Sorry to dig up an old thread but here is my take on the Albino genetics. Hopefully it will help others understand the concept..

1. We already know that Albinism = lack of dark pigmentation, so I won't bother discussing that here.

2. Albinism is a recessive trait so it needs a double dose of alleles for expression.
In other words it will only be visible if paired with another recessive allele (another Albino OR a carrier of the gene).
Any animal expressing an abnormal trait is in possession of a matched pair of recessive alleles, hence we should cull any deformed animals. If we breed from these deformed animals we muddy an entire gene pool (including those that may look healthy as they are still carriers - keep reading on to understand)...

3. So a single dose will not display the trait - Albino x common will produce 100% Hets (Hetrozygous = carrier of the gene).
100% of course means the entire clutch, so we can be sure to know exactly what we have produced quite easily here. These would be normal looking animals that are carrying the gene.

4. Now if we put the parent over a sibling (Albino x Het) we get a 50/50 clutch.
That is 50% Albino & 50% Hetrozygous. Again we know exactly what we have produced. The white ones are Albino & the normal looking ones are carriers lol. This is also true for common x Het. You will get 50% commons & 50% Hets. However there is no way to know with certainty which are carrying and which are not as all will look normal, so it really is a waste of time...

5. Now here is where it gets difficult. Putting a Het over another Het = 50% Het, 25% Albino & 25% common.
As the Hets & commons look alike we have no idea which is which. So these are called 66% Het as there is 66% chance of them being the carrier (although its actually more like 33%) or as commonly used these days the term "possible hets" meaning they may possibly be carrying or may possibly be not haha. This is where problems arise as what we think are just normal animals may infact be carriers and will produce Albinos if mixed with others also carrying the gene.

NORMAL x NORMAL = 100% NORMAL
ALBINO x ALBINO = 100% ALBINO
ALBINO x NORMAL = 100% HET FOR ALBINO
NORMAL x HET = 50% NORMAL, 50% HET FOR ALBINO
ALBINO x HET = 50% ALBINO, 50% HET FOR ALBINO
HET x HET = 25% ALBINO, 50% HET FOR ALBINO, 25% NORMAL


AA = Normal
aa = Albino
Aa = Het

The problem is this:

In BN, Albino X Albino does not give you 100% albino. Sometimes it does, but there are many many documented cases where two red eyed yellow true albino fish produce some or all normal brown fry.

Amber wrote:

The problem is this:

In BN, Albino X Albino does not give you 100% albino.  Sometimes it does, but there are many many documented cases where two red eyed yellow  true albino fish produce some or all normal brown fry.  

Amber, I'm agreeing with you. Thanks for starting this thread. I bred a Albino female to a Normal male. The result of the Albino X Normal cross was 25% Albino. I couldn't figure it out. I expected 50% X 50%. If the male had a hidden dose of Albino. Your stating that there are two types of Albino besides a Blond with dark eyes was the key. Thank you...
Now it makes perfect sense...

Oh,  BTW: I figured out that, when one of us buys a BN from a LPS now days; we have no clue as to what hidden genes a fish may carry...

I in no way understand genetics past basic Mendelian genetics, but I remember it has been theorized here before that BNs do not follow basic Mendelian genetics and that it may more closely resemble that of reptile and a 3 gene concept. I wouldn't know how to elaborate on this concept further though.