japan blue on x chromosome

Does anyone know how to tell if a female guppy has japanblue gene on x chromosome?
For example, how about the female guppy in the link below?

The japan blue gene can also be on the x-chromosome. If that's the case, a female often shows a part of blue on the body or in the finnage. Which is the case in the female in all three pics.

I bought my first Endler from je nais cest PAH yesterday.
He has a blue lyre tail/half body and could be a brother of the young lady above.
He’s a handsome chap to be sure and MrsLurch reckons her lady endlers are already frothing at the gills to get into his quarantine tank. To be honest I think she’d be in there herself already if she was still a mermaid.

emeraldking said:

The japan blue gene can also be on the x-chromosome. If that's the case, a female often shows a part of blue on the body or in the finnage. Which is the case in the female in all three pics.

Click to expand...

Sorry for thread hijack but as I’ve just mentioned above I’ve recently acquired a lyretail Male with identical colouring to the female above. We‘re thinking of trying to breed him with one or more of MrsLurchs female endlers.
Some are all silver and some are silver with touches of black in fins. Which would you recommend?
How many females would you put into his tank? One? Two? Both at the same time? One at a time?
How long for? One day? Two days? A week?

Her females gave birth two days after she got them home from the lfs early last year which wasn’t the plan. There’s only been two fry in the last six months so we’re hoping that’s the end of that little bout of madness.
Were gonna up the temp in an attempt to get more males.

ClownLurch said:

Sorry for thread hijack but as I’ve just mentioned above I’ve recently acquired a lyretail Male with identical colouring to the female above. We‘re thinking of trying to breed him with one or more of MrsLurchs female endlers.
Some are all silver and some are silver with touches of black in fins. Which would you recommend?
How many females would you put into his tank? One? Two? Both at the same time? One at a time?
How long for? One day? Two days? A week?

Click to expand...

I've copied two of those photos that the topic starter linked to. Above shows a male and below shows a female with blue in her finnage.

Using a japan blue male (no matter the shape of the finnage) to cross to a non-japan blue female will result in japan blues when it comes to the male offspring.

In your case when using those females with some black in their fins, means that your black finned (or parts of it) females carry a dominant trait from the line they're coming from. Which means that a certain trait is x-linked. It's got probably something to do with the color black that occurs in the male siblings. Which will show up as well in the male offspring. You probably don't know if those females came from a certain endler strain of just a mix. The silvery females with no coloration in the finnage will produce normal japan blue male offspring.
The color "japan blue" is a very dominant trait.

Well, him and couple of virgin or clean (not storing any sperm packets of a former mating) females will be fine. And you can put them together in one time. And just leave them. Because it's the female that will decide wether a male is allowed to mate with her or not. despite of the mating efforts of the male, a mating can be done is a split second when they're in one tank or it may take a while before a female will let a male mate with her. For it does happen as well that a female doesn't want to mate with a certain male.

emeraldking said:

The japan blue gene can also be on the x-chromosome. If that's the case, a female often shows a part of blue on the body or in the finnage. Which is the case in the female in all three pics.

Click to expand...

Thank you.
I might buy this fish and reconstruct a strain.

This is the strain that I want to modify.
This is hybrid of wingei and reticulata.
What I want to change is the blue color in his tail.
I want to make the tail clear , just like wild endler's.
I don't want the grass like color in tail.
Is there any good idea?