I'm thinking of setting up an all-guppy planted tank and I was thinking of setting up a tank of just one variety of guppy - for example, just blue grass male and female guppies.

What I am curious about is whether when the guppies breed, the next generation will remain as blue grass or am I likely to find that although the parents look blue grass, the fry may have other colour genes in them? And, eventually, would my tank of blue grass guppies will become a tank of mixed colour guppies?

I want to know this because I don't want to spend a lot money on buying just one variety of guppy only to find that the end result will still be mixed guppies anyway. I might as well have spent the money on getting more mixed guppies rather than getting less single variety guppies.

Thanks.

In order to understand the term of breeding true, you need to understand the genetic behind the strain you are seeking for. Breeding true however doesn't mean you get 100% of the same strain. It is a relative term and a very subjective one too. Some breeders consider 70% of the dropping similar to the parents as breeding true. Some may say 80% and even up to 90%. The other part is the genetic behind a strain. For Blue Grass they can drop Red Grass, Multiple colored Grass (red+blue and in between) and also Blue type (body color variation). But they are Grass strain because similarly a Red Grass will drop Blue Grass because the gene is interconnected. Fancy guppies are selective bred for decades to come to it's current state. It's not as simple as it looks to a beginner and there's a learning curve to it. To maintain a particular strain, you need to diligently select your breeders for each generation to weed out unwanted variation. There's a possibility to downgrading a strain of guppy if there a left to breed ala harem style. So it depends on your final objectives. If you don't mind second grade looking grass patterns then let them be. Hope this helps as I can't explain everything here. You need to do some reading to understand more........good luck on your guppy venture

Thanks. I geddit - I think.

To summarise, even if I start with a tank full of, for example, blue grass guppies, as the successive generations are born, other colours of grass will appear over time. This is because grass guppies are the result of cross breeding different colours of grass to produce the end result.

If the above summary is correct, will I end up with just varied coloured grass guppies or will the fry eventually show other varieties, not just grass, coming through?

Please let me know.

Thanks again.

Partially correct.

The Blue Grass pattern was not created by selective breeding of other grass color but through selective breeding of snakeskin with another strain which I'm trying to guess as well because not much was documented. The Grass pattern was created by Japanese.

Yes you would end up with varied colors of grass and also other varieties depending of the source of your grass guppy. I've known people who crosses blue grass with blue tuxedo to enhace the blue color of the grass and to add fresh genes into the much inbred guppy. So when these other genes are injected, it will be certainly shown in their offsprings once the genes matched/sequenced. And this calls for understanding of the genes - dominant, recessive, co-dominance etc. The other thing to consider would be the deterioration of the grass pattern. Grass is defined as fine dots. If not given due selection on the breeding pair, it can deteriorated into leopard pattern meaning bigger dots, or broken lines as a result of joined dots. Worse case scenario is turning into a mosaic pattern which is not desired in a grass guppy. Anyway all this are for high end breeders like myself. Given the difficulty to maintain a grass strain, I opted not to keep them seriously rather using it as a tool fish to create my signature strain

Thanks.

You've really been a great help. Since my intention is not to breed a particular strain of guppy, I'll just set up my tank with mixed guppies and let them inter-breed happily. It will also cost me less to acquire the guppies since I won't be looking for a single variety of guppy but will just get whatever is pretty!!

Ooooh, now I'm getting fired up thinking about setting up the guppy tank next week.

Thanks again.