Pleco question about what % of fry ...

[traco1]

Not knowing diddly about genetics, recessive genes, all that "thinking" stuff, I thought I'd post and see if anyone knows the answer. I'm looking at some fry whose parents were a Red Marble and Albino as well as more fry from a Red Marble and Brown (all Long fin). These fry are dark brown to black with white spots.

Any idea what I will get for offspring from these fry if bred to each other? Trying to learn genetics and percentages if breeding A with B = ? http://www.plecofanatics.com/forum/images/smilies/new/huh.gif <------ that's me, totally confused! lol

[KnaveTO]

strange thing is... I have seen tons of genetic studies done with guppies and with angels... beyond that I have seen nothing anywhere for any species of fish.

[traco1]

Thanks Ross, I thought it'd be an easy answer, you know, 25% albino, 25% brown. Hate to buy them and all they produce is brown BN plecos, would be nice to have some variety. Hopefully, someone will know the answer.

[KnaveTO]

I would assume the genetics would be similiar to standard genetics is that x% would be albino x%brown... however you would need to at least have an idea as to what would be the dominant and recessive gene for the red marble and the brown. We all can be pretty sure that the albino is the ressive with that mix. I do know that tails is about a 50/50 mix..

sorry... about the best I can do for you. If you want more info there may be some help on www.plecofanatics.com (http://www.plecofanatics.com) or www.planetcatfish.com (http://www.planetcatfish.com)

[Pamelajo]

Hi Barb this probably won't help you.
In one tank I have a female albino bn (pure) one albino male not pure and all they produce is brown bns, never seen an albino from this couple.

[Melody]

That's interesting - albinoism is generally double recessive, which two albino-eyes should bring into dominance. The brown must be one very strong dominant... maybe the albino female has some brown in her recent ancestry. They should still throw a percentage of albinos though. Thanks for mentioning it, very intriguing.:yes:

[Pamelajo]

She has a male and female sibling that have paired up and they only produce albinos, and have had quite a few batches. I had expected some albinos from her, but none so far and I think they have just had their 4 or 5 th batch.

[Melody]

The gene 'colour' isn't necessarily inherited by all offspring, so that's reasonable enough, but by all logical assumption, she would throw at least a good percentage of albinos when paired with an albino. Maybe there's something unique in Pleco genetics that I don't know about though - I'm certainly not educated in that respect.:Think:

[traco1]

Wow, see what I mean? Genetics, recessive genes, ... I know so little. But have to start somewhere, reading experiences here helps.

[Pamelajo]

I don't know much about genetics either. But I also thought that she should be having some albino babies.

[traco1]

I thought the same with a koi female swordtail throwing some koi. Not a single one coming from her has been a koi, beats me!

[Melody]

My official, learned and wise opinion is...

Pam has a weird fishy!

Or I don't know everything... but what are the chances of THAT?

:laugh:

[Melody]

I thought the same with a koi female swordtail throwing some koi. Not a single one coming from her has been a koi, beats me!

I've heard that about Kois before actually. Nobody knows who developed the strain, so we don't know the genetics behind it for the most part.

[_BaDgUy_]

Genetics is pretty much the same for all fish!

For one particular trait to come out, both parents must have the according gene!

Example : Red marble male and albino female
Their offspring will both have the red marble gene and the albino gene, but probably not showing any parts of it, or being plain brown ancistrus!

For the wanted trait to come back up, you have to either cross an offspring with a parent, of pair up two offsprings of the same batch.

I have to look into my genetics books for the exact percentage. I'll come back with exact numbers!

[traco1]

Thanks for that info. I just assumed that if I had a female koi sword and say, a standard orange sword male, some of the fry would have koi markings. Goes to show how much I know, heh?:eek:

I guess I should never assume.:laugh:

[_BaDgUy_]

Here we go for some precise answers!!

Might not be the exact percentages for the example given, as the red marble is not a dominant gene, but it gives you a good idea of the results.

Reproducing offsprings with offsprings of same generation :
Assuming F0 = Red marble x albino will give F1 offsprings
F1 will be red marble with albino genes will give F2 offsprings
F2 will be 75% (50% pure red marble, 25% red marble with albino gene) red marble and 25% albino

Reproducing offsprings with parents (backcrossing)
Assuming B0 = red marble with albino gene (daughter) x albino (father) giving B1 offsprings
B1 will be 50% red marble with albino gene and 50% albino

Hope this helps!

[Melody]

Genetics is pretty much the same for all fish!

For one particular trait to come out, both parents must have the according gene!

Example : Red marble male and albino female
Their offspring will both have the red marble gene and the albino gene, but probably not showing any parts of it, or being plain brown ancistrus!

For the wanted trait to come back up, you have to either cross an offspring with a parent, of pair up two offsprings of the same batch.

I have to look into my genetics books for the exact percentage. I'll come back with exact numbers!

That's when you're dealing with recessives that require a double dose of genes. Not all traits require both parents to carry the gene to result in the trait showing in the offspring. In the case of albino genes, they're double recessive so your explanation applies, as both have to carry the gene to make it dominant. The fry then have to inherite the gene from both parents to show the trait.

The pleco-specific information is handy, thanks for posting it!

[traco1]

It will help, thank you very much. Myself and others too.:smile:

[traco1]

That's when you're dealing with recessives that require a double dose of genes. Not all traits require both parents to carry the gene to result in the trait showing in the offspring. In the case of albino genes, they're double recessive so your explanation applies, as both have to carry the gene to make it dominant. The fry then have to inherite the gene from both parents to show the trait.

The pleco-specific information is handy, thanks for posting it!
I'm getting a headache. It sure is not an easy answer or a quick result you would see if breeding, you are talking 1,2, and more generations before seeing if your fish is producing the gene? Holy cow, impatience does not pay for this, does it? I bow to you breeders who are doing this, generations further down the line.:notworthy:

[Melody]

... and I don't know the half of it....lol. I read an article or a post once... can't remember who posted it, probably Jim, but it was an ALA master regardless. Anyways, by the time I was finished reading I was using both hands and mumbling to myself, using fingers to try to keep track. Then I tried it on paper in different colours of ink. Then finally I replied as any intelligent woman would ...

"Ya wanna post that in English for me?"

LOL They have the patience of a saint.

It is NEVER cut and dry, there are always exceptions. For example, the Hifin gene is thought to be, or have been, a fatal gene. If some fry inherited it from both parents, they'd die. It was proven by many breeders. But then lately, something changed, and now some strains seem to do just fine when both parents are Hifins. That's what's so fun about it - there's always something to learn.:yes:

[traco1]

Thanks Mel.:Flowers3: