con-man-dan wrote:i recently crossed a PF and GM and got nothing but grey juvi's! i had moved most of them to a seperate tank, the culls were eaten, and 3 somehow were left in the parents tank. I'm thinking about crossing what appears to be a lovely male with his momma to see what happens now that he'll have the pink gene, and the fry would have 2x pink gene, right?
You got all grey because your "GM" was homozygous for the "grey" gene. We'll call that AA. You're pink female is homozygous for the pink gene. aa for short. So all your fry would be grey, but carry the recessive pink trait (100% Aa).
If you were to then cross the "new" grey male (Aa) with his pink (aa) mother you'd get 50% pink (aa) and 50% grey (Aa) but carrying the recessive trait (heterozygous).
ohcustoms, I don't think it will be possible to get 100% marble cons, because with the "marble" cons you're not just looking at one allele and, using probability, there is a pretty high chance in a spawn of hundred to get "marbles" that are all grey or all pink.
We've been selecting animals for certain colors for hundreds, if not thousands of years. If you just search around you'll find lots of articles on coat coloration. Here a a couple that deal with cats. Just imagine it's a fish instead.
http://www.geocities.com/Heartland/holl ... colort.htm
http://www.geocities.com/Heartland/holl ... incomplete dominant