18

In preparation for creating this series of articles on guppy breeding I moved all of my guppy strains out of my items folder leaving only the CD guppy files along with the Albino20 and Kcobra20 .fsh files available to me. I wanted to pretend that I was starting from scratch armed with only the most rudimentary of guppy strains and see how quickly I could produce fixed strains of what I consider the basic phenotypes. The wild card in this approach was the possible appearance of a guppy with pastel pectoral fins that was not the easily found "albino Christmas red with pink pectorals" found in the Albino20 .fsh file. (Though, I must admit, I must have seen the pink pec albino dozens of times before I actually noticed the trait.)

Albino guppies with pastel colored pecs are hard to spot in three-month-old batches of males. Only when the guppy shows you his butt or looks at you head on does one notice that the pectoral fins are indeed pastel colored. The two phenotypes necessary to produce the possible appearance of this trait is "clear any color" and an albino strain with "some shade of orange in the tail". I realize that these are rather vague parameters but that is the best I can do at this time. We have two such strains available to us to utilize in our fishing expedition for pastel pectoral fins: "Clear Christmas red" from pool one and "albino tux tiger topaz with pumpkin stripes" from pool seventeen.

Here are males from these two strains we will be out-crossing:

Because I enjoy working with albino tuxedo strains I selected a female from the "albino tux tiger topaz pumpkin" strain and a male from the "Christmas red" strain. The albino strain has orange in the pumpkin stripes which just might meet the criteria of having "orange in the tail" previously mentioned. Just what color pectoral fins might show up is unknown at this time. (I have been able to produce "go light green", chartreuse, yellow, and baby blue in the past by experimenting with various strains I have on file but I have only these two strains with which to work at this time.) We will not see albino males until the F2 generation and we might have to explore several F2 generations to expose the pastel pectorals AZ might be hiding. Enough talk, let's throw a pair into the tank and see what happens.

Here are the males produced in the F1 generation.

As you can see they look exactly alike, positive proof that both strains used to produce this F1 generation were stabilized.

I selected a random pair from this generation (the first male and female in the file) to produce the F2 generation.

Here are the males produced in the F2 generation.

Well, well, well, lookie, lookie, lookie at what we have here! Two albino males have "baby blue" pectoral fins. This "clear multi" tail pattern tips me off to look for the pastel colored pecs. Whenever I see this albino phenotype I immediately check out the color of the pectoral fins. For whatever reasons, AZ combines this tail pattern and color with the pastel pectoral trait. I have discovered that the trait is sex- linked, like the cobra body pattern (at least so far, in my experience to date). Both of these males are non-tuxedo so we hope to find a tuxedo female when we mate one of these guys with one of his sisters to produce the F3 generation. I will not be searching for the "right sister" in this chase. I have the basic phenotype I want and I will use back crosses if AZ tries to throw me off the trail as we move through the generations.

Here are the males produced in the F3 generation.

We see four phenotypes in this generation and not one of them is like the father. The voice of experience tells me to back cross a female from this generation with the "Mr. Blue Pec" from the F2 to produce the F4 generation.

Here are the males produced by pairing dad with one of his daughters.

Here we see five phenotypes. The daughter we used was not a tuxedo female as demonstrated by the presence of non-tux males in this batch. The "yellow/orange and red" leopard males (#1 and 2) are very interesting and we can save their phenotype for later investigation. I always breed for color intensity so I select male #5 to sire the F5 generation.

Here are the males produced by male #5 and one of his sisters as our F5 generation.

We have narrowed the gene pool down to three phenotypes. Looks like we have the emergence of a heterozygous trait in this strain. Many "clear multi" strains are heterozygous strains, not all, but most. I select male #3 to pair with one of his sisters to produce the F6 generation.

Here are the males in the F6 generation.

Here we see a possible tertiary (is there such a word as tertiozygous?) phenotypical (is that a word?) development in this gene pool. The way these new phenotypes keep showing up one would think we were doing a series of back crosses. Sticking with the program I selected male #1 to produce the F7 generation.

Here are the males in the F7 generation.

Nice! The sister chosen to produce this generation was a lucky choice. I think phenotype #2 is dazzling. However, we gotta stick with the plan and see just what this blue pec strain is going to include. Since we are at the F7 generation, the gene pool should be becoming shallower. Are there any more surprises up AZ's sleeve? Selecting male #1 we move on the F8 generation.

Here are the males produced in the F8 generation.

These guys are just like their uncles in the F7 generation.

Just to make sure we have purified this gene pool to the extent Mother AZ will consent to I select male #1 to produce the F9 generation.

Here are the males of the F9 generation.

I think we have a stabilized strain of guppies in the tank. (I checked several pairs using TransWarp and the strain passed the test by producing batches all looking like the F8.) The strain is heterozygous for two phenotypes, "albino tux clear multi tangerine/canary with blue pectorals" and "albino tux clear burnt orange/tangerine". If I use a blue pec male to father each generation I will always see these two phenotypes. Again, this is what I refer to as a fixed strain heterozygous for two traits. Usually, when you have this kind of situation one of the phenotypes can be separated and stabilized as a homozygous strain. Let's see if we can also fix the "burnt orange/tangerine" phenotype in a generation or two. From this batch we select male #1 to produce the F10 generation.

Here are the males produced in the F10 generation.

Poof! Another potential homozygous strain for our breeding pleasure. (Mothers don't let your guppies grow up to be hetero….. Better stop here. Let's not go there. My wife makes me do it!)

Throwing caution to the wind I select one of these males to produce the F11 generation.

Here are the males produced in the F11 generation.

There we are. One homozygous strain of "albino tux clear burnt orange/tangerine" in just two more generations. Not bad! See how straightforward this creative process can be!

Here are the crosses made to create and stabilize these two strains as they appear in my "items" folder.

I have been able to stabilize only two versions of the pastel pec albino as homozygous strains, the "albino Christmas red with pink pecs" and a "white albino snakeskin with baby blue pecs" strain. All other pastel pec strains that I have been able to stabilize have been of the "clear multi" phenotype and are heterozygous for some other phenotype. I have yet to see a non-albino strain with pixilated pectoral fins. Perhaps one day I will trip over this phenomenon, you just never know with Mother AZ.

I have judiciously used the technique of back crossing in many of the previous pools. Let's throw caution to the wind and see if we can create something new and wonderful by aggressively using a series of back crosses to really make Mother AZ work her magic in the next pool.

AGGRESSIVE BACK CROSSING CAN BE FUN