I haven’t figured out why my axie has red spots the vet can’t either

[Nicholas d]

My Lucy axolotl has had these red spots all on his body. It’s most visible don his tail
They don’t seem to be affecting him.
He’s eating about 3 euro night crawlers a day. He’s in a 33 long with sand he was previously in a 15. I have him tubbed now because I’m adding ammonia to the tank to ensure it has enough bacteria for 2 axies, only did this because I upgraded the tank and plan on getting another axie. She is a presumed 8 month old she’s not lethargic or anything and the spots aren’t raised. I took him to the vet twice they said they could do a biopsy but it may be inconclusive, it was 200 dollars so I didn’t do it. They said that he might just be developing pigment, but I’m not sure the vet said it’s definitely not red leg. So that’s a relief. Any input would be extremely helpful cause I’m feeling hopeless as to finding the cause of this. I will attach parameters and pictures below.
ph: 7.8
Tank is cycled
20 ppm of nitrate sometimes 40

 

[AMurry24537]

My golden has the same thing, but only on his head (I'll add a picture below). Someone on here once suggested that it might just be some kind of genetic coloration or something like that. It doesn't seem to have made any difference for my guy, who is currently a chunky 12-inch long monster who can never stop eating. As long as your tank parameters are good and it doesn't exhibit any other signs of sickness, I wouldn't worry about it.

 

[Nicholas d]

This makes me feel better he seems very happy and chonky

 

[akiso914]

I just had exactly that happen on my leucy a couple weeks ago. I tested parameters and they were fine (0,0,10) but she seemed a little uncomfortable, and was swimming a bit more than usual. still eating and everything normal. I tubbed her and changed 50 % water. red spots went away in the tub. spots came back when i put her in the tank but she was calmer so i just watched, and now two weeks later no spots and no signs of spots. The only thing I can think of is I fed her a wild earthworm from outside and I wonder if it had something irritable in it. Otherwise nothing had changed before the red spots showed up.