How to well crayfish sex

[Perk]

Hey guys, I've several questions here:

I was looking at some of the blue crayfish my LFS was selling. The thing was, they couldn't really tell which ones were female and which ones were male since the crayfish were pretty small (probably about 1" long). I believe the males have one extra swimmeret where the abdomen and the thorax meets, but the LFS guys said it was difficult to tell when they're that small. I wanted a male and a female, but if what they say is true, then how would I go about doing that? They do sell large ones, but they're insanely expensive.

Also, I saw that the crayfish had different colors. One was very pale blue with a hint of light brown/red on the sides of the head, and the other was darkish blue. What's the difference between the two? They listed them both with the same name. Could I breed the pale blue one with the darker blue one?

Any help would be great! Thanks

 

[Aquarium1]

Sexing Crayfish
Breeding Crayfish
Hope I helped. Its not very easy from what I've read.

 

[joy13]

The brighter blue one probably molted lately.

 

[Perk]

Thanks for the links. They were an interesting read. However, those pictures depicted pretty large crayfish so the sex difference was pretty easy to see. You could clearly make out those extra swimmerets.

So I guess it's not possible to tell the difference at a young age? Should I take a chance and buy another one and hope it's a male?

 

[biomanz]

If they're Australian Red Claws, males will have a red patch on their claws, when they're at least 2.5 in long. If those crays are pale white blue then they recently molted - if they're very dark blue they might be molting soon.