Illness/Sickness: Something wrong with gills? Fungus?

Hey everyone,
My youngest and smallest Axolotl (Gideon) over the last couple of days has had one of its gill stalks shrinking a little, it doesn't look quite like the others and I'm wondering if it's a fungus or something that I should worry about?
He's currently living in a plastic container as he's too small to be integrated with my other two Axies, and I change 100% of the water every day, treated with prime. All levels are in normal range according to the API master test kit and the container stays between 18-19 degrees Celsius at all times.
Gideon is also eating small pieces of earthworm and frozen bloodworms.
Thanks for any info and input, maybe I'm just being an over-concerned Axie owner haha.
Here's some pictures, it really only looks like the first stalk on the right side of its head that's kind of funny!

Look at his little face, he's so cute. :happy:

I can see what you mean about the first one on the right, but to me it looks more as if the feathery gills look a bit disorganised, which make it look different from the other gill stalks.
I don't know if that means anything health-wise, but hopefully one of the more experienced keepers will be able to offer some advice.
As you are keeping the water parameters within range and as Gideon is still eating, I'm not sure if it is anything to worry about, but keep us updated on his general condition and see if anyone else can offer advice.