How to tell if sexually mature?

I bought my first axolotl from a pet expo in February. He was around 3-4 inches long then. The guy didn't seem like answering my questions and just wanted the money so I have no information on how old he is. He's around 6.5 inches now.
I recently bought 2 juveniles from a very well informed owner who tried breeding for the first time, and the two I got from her were born in this last October, so I know how old they are. They were around 2 inches when I got them late March, but they've already caught up to my other guy in size--much quicker to grow than my first axie.

I read somewhere that you can tell that they're mature when the tips of the toes start to darken, but of course, the one I'm curious about is black in color.

Is there a way to tell if an axie is mature when they are darker?
Thanks. :happy:

Dark ones get white toes and they seem to change colour more when they've stopped growing rather than the sexual maturity. If you're hoping to breed them though I hear you should wait until they are about a year and a half

Definatly toe colouring, mine is 6 and 1/2" and is 8 motnhs old, but i think he grew slow haha
My others are 5 and 1/2" and are around 6 months old.

Oh and as a reference I'm guessing mine were between 9-11 months when they stopped growing (all between 23-26cm long now!) and all have coloured toes

Toe tips are not an accurate representation of sexual maturity.

Really, the only way to tell for sure is when you see eggs/spermatophores. Most will reach sexual maturity within a year (but some will take 18 months or more!), and around 7-8 inches in length.

As far as I know.... black toe tips don't have anything to do with sexually mature axies, but it's a sign of them 'growing up'. I've seen it on young axies too and they didn't look sexually mature'ish to me.

And I agree with Kaysie.