I'll say this as my last statement for this thread, as you aren't getting my point. The fast and easy approach to getting what you want and using science to get fast without fully understanding what the ramifications of the outcome (yes science is trial and error, and you are talking about deforming a LOT of fish to get to your end result). Selective breeding to get the end result you want, doesn't play around with the genetic factors that make that fish, that kind of fish. Intentionally causing genetic mutations over and over again until you get what you want. AND, you are talking about doing it purely to engineer a pet, and not for some other purpose other than commercial gain.
Your point is "why not engineer it here and now?". However, you keep missing the point of if it SHOULD be done at all. Genetic engineering is something that should NEVER be taken lightly, and to do it just to make a pet or make a profit from making that animal is not always the right thing to do.
My point is, just because scientifically we have the ability to do something, does not mean people should.
Good post CCM. Pir, scientific research on animals is extremely strictly regulated. For my PhD work I had to take classes on proper animal care and control, and ethics, even though I was only working on in vitro cancer cells. I don't know of a single IACUC committee that would approve of doing what you propose. All research protocols are formulated to keep animal sacrifice to an absolute minimum. You would be able to do it privately, with private funding, but that doesn't make it ethically right. Like I said, I had to take all sorts of classes on care and ethics for my research on cancer cells.