Strange circumstances with my axolotls.

[Yeroc]

My girlfriend and I both have a few axolotls that share a tank together but two of them have a particular feature I'm curious about and can't seem to find any answers. One in particular is her hypomelanistic axolotl has always maintained a partially open mouth. The only time it comes close to fully closing is when biting down on something in his mouth. The second axolotl had its hand bitten off accidentally a while ago and though its healed he appears to be growing a second hand thats shaped but not complete in the fingers length. It has been affecting his balance when swimming and am not sure how to handle that. Any insight would be appreciated.

 

[ManderMomma]

Axolotls growing extra limbs isn't really all that crazy. Mutations happen all the time in regeneration as a regenerated limb never really regenerates properly, meaning that even a small injury could trick the cells into growing a new set of fingers.
It's very common with gill stalks. My axolotl has a split gill stalk, resulting in her having 7 gill stalks total (instead of 6).
I'm sure that your axolotl will eventually get used to the extra limb similarly to how animals get used to a missing limb. Here's a photo that I had stumbled upon when researching axolotls before I got mine that seemed interesting that explains extra limbs.

As for the open mouth axolotl, I'm not sure. My best guess would just be that it is forgetting that it has it's mouth open, somewhat like how cats can forget to put their tongue back in their mouth.