Male Guppy Fry Tails?

I have 2 male cobra guppy fry that are 10 weeks old. How old are they when their tail grows into the big fan? I want to see what they look like before I give them to the fish store. These guys have gotten many of their black body spots but their tails are still around the same size as the females. Maybe just a small tailed variety from the mom’s breed then?

I’ve included pics of the mother (blonde with a red tail), father (yellow cobra tail) and one of the male fry who has a red tail and though you can’t see it because he’s pulled his tail in tight trying to mate with the black female in the photo, he’s got a red tail with black spots and a few spots on his side. His brother looks exactly like him with fainter spots. His one sister is identical to mom and the other looks nothing like any of my fish and doesn’t have all her tail color yet but looks to be black with an orange stripe at the top.

 

It's a gradual change, you will barely notice it until the process is complete, but they should look like adults at about 5 months old or so, and I imagine their tails will be fully developed or near developed after that!

 

It's a gradual change, you will barely notice it until the process is complete, but they should look like adults at about 5 months old or so, and I imagine their tails will be fully developed or near developed after that!

Ok, so a couple more months. I’m not the most patient person but I’ll try to last that long!!

 

Some fish do not develop the delta tail, if the mom was not a virgin when you got her (aka if she did not come from a breeder that keeps males and females separate she was not) so was pregnant by a different male than the cobra you have - so it is very likely that her offspring you are waiting on to develop delta tails will not - my red female drops very nice blond babies, but her first drop was by a different male than her current drops parent, the offspring have not developed delta tails and will not, the males look more like a flame candle (they have a snakeskin type pattern so the male she bred to was likely a cobra).

 

Some fish do not develop the delta tail, if the mom was not a virgin when you got her (aka if she did not come from a breeder that keeps males and females separate she was not) so was pregnant by a different male than the cobra you have - so it is very likely that her offspring you are waiting on to develop delta tails will not - my red female drops very nice blond babies, but her first drop was by a different male than her current drops parent, the offspring have not developed delta tails and will not, the males look more like a flame candle (they have a snakeskin type pattern so the male she bred to was likely a cobra).

Ok, that makes sense. I had her for about a month before she got pregnant so I partly just assumed that that cobra male was the father. They’ve been attached at the hip since before that and when I almost lost him 4 months ago (he just laid on the bottom) she was still within millimeters of him 24/7. Then they started chasing each other around and he tried mating with her. 4 weeks later, she dropped her first batch and is now 2 weeks pregnant with her 3rd. Every 4 weeks she has another drop. I think she had to be a virgin because she was quite small when I got her and the males completely ignored her for a few weeks. Who knows though