Question: Slimmer Axies?

[Toothless_103]

I have 3 almost 4 month old Axolotls (At least I think they seem more 5 almost 6 month old to me). I feed them all the same amount of bloodworms and at the same time of day. For some reason, I have two that are still slimmer, one is slightly wider than the other, but then I have a wider axolotl, even the head is wider- just overall a larger Axolotl. The slimmest one is longer than all of them but one of them is a bigger, I almost want to say "bulkier" Axolotl. Is there a reason for this? Is this normal?

 

[xxianxx]

Females are generally fatter and have a broader head than males, this sex difference is not normally noticeable in such young axolotl though, so its probably just a difference in growth rate.