I have realized in the last two weeks that within my group of about 50 fry, the ones starting to show tendencies towards the calico colors are the biggest on the group. About 1 in 5 of the fry are going the clear/white that last year was the start of calico colorings. Of that group of about 9 fry, 3 of them are the giants of the entire group, about twice the size of anyone else. The remaining 6 or so that show the calico tendencies are also on the largest end of average for the rest of the fry currently.

All other distinguishable features such as normal or black eyes, tail types (I seem to have 3 distinctly different types here), and size of the dorsal fin in proportion to the body, are pretty evenly mixed between the calicos and the rest of the fry.

I am wondering if anyone else has ever noticed a correlation between the coloring of fry within a single spawning group, and the rate at which they grow within the same group. Last year my single fry that grew faster than the rest was also a calico.

I know that I still have a relatively small sample size to work with here, but it strikes me as odd that every single calico would be at the top end of the size ranges for this group. So, coincidence; genetic abnormality resulting from the particular combination of genes from my adult fish; or somewhat normal genetic occurance?

This also make me worried because often the largest fry end up dying at one of the developmental milestones. I would like to have a surviving calico fry or few. I am wondering if these particular parents produce an unstable genetic offspring when the calico coloring is displayed. I really wish right now that I had that book on goldfish breeding and genetics.

Try Joseph Smartt's GOldfish Breeding and Genetics.

IT does not specificallycover your questions, but it is a GREAT book for genetics and breeding practices.

As far as the "larger" ones being calico - I think that has almost everything to do with your particular cross. Calicos do take on their adult colors earlier than reds and blacks/blues, but they do not ALWAYS have to be the biggest. In your particular cross, though, it may be that the genetic combinations that are the strongest are also the ones that produce calico. You have just been particularly observant and have noted this. Good for you.

I also have found that the largest fish are often the ones that end up dying at the "milestones". I hope you get some that make it through to adulthood.

So then if the large ones die at those milestones, are they really the strongest of the genetic matches?

No - not overall. My theory - and it is ONLY a theory - is that various body constructs do better or worse in life. A deep bodied fish - with a short, deep barrel body - can have difficulties in digestion - the insides are all squashed up. In a little fish, they may work well - extraordinarily well - as the fry is growing. The fry digests well - and outshoots it's spawn-mates. But, as the fry gets older, it has more and more trouble with....say, swimbladder control or constipation or whatever, and it becomes a floater - and thusly dies.

Other fry die as their bodies - which may work very well for a certain size - outshoot their ability to process food - or to deal with ammonia or nitrite or nitrate or somesuch problem.

It is a big question mark. I have done enough crosses within a single line of fish now that I know exactly what type of fry will most likely not live just by looking at them. Unfortunately, it is often the ones that look the best, early on.