3.5 month old bloat? or chubby?

[Kirzzin]

Hi guys this is Gus-Gus. In the last few days I've noticed he is a lot more plump than his siblings. He isn't the largest or the smallest of his siblings, but he is the only one who looks like his organs aren't right up against the sides of him.
He is eating and pooping as normal. What do you guys think? There are no vets around here that even know what an Axolotl is.
Here's some photos I screen shot from a video of took of him.

 

[Holly12]

I have no experience with axies that young, but I will say, Gus Gus is adorable!

 

[AxolotlChris]

Certainly looks bloated. Usually if it was trapped air it would be floating a lot. If it was blood worm it had eaten the stomach would be much darker. Hard to say