Most likely pyromelana take longer to mature because in the wild they live in high mountain places with harsh weather conditions, where growth would be slower than those species who live at lower and milder elevations. So even if they get artificially larger in captivity, other factors are in play governing their maturity. At least that is my theory! LOL!
Zafina and Zane live together full time. When they are ready to mate they will do it. I am not worried about them doing it too soon. The little 08 male is not in breeding mode at all; he could smell the pheromones of my other two mature females in their other cage this spring and it did nothing to his libido, or lack thereof. He has been eating well this year, a first for him! I had another little female, Zafina's half sister, in with them, but Zafina outgrew her little sister by twice as much so I put Zuni by herself, thinking she is too little to be with the other two.

Zuni last June. She likes to eat, too, but her half sister is voracious.
-----
Bob
Pyromaniac AKA Greatballzofire
Keeping cats allows man to cohabitate with tigers. Keeping reptiles allows man to cohabitate with dinosaurs.