Wild type's tail acting up?

[Lyssa]

So my wild type axolotl's tail, who is probably about a year old now, is starting to become clear at the tip, and looks very thin, almost like its just one layer of skin. And it has small red spots on it. He doesn't show any signs of stress, and he eats fine. I don't really think its life threatening, but it's just starting to bug me since I don't know why, and I can't really seem to find any information about it.

Does anyone know what happened? Or is this common? He did snag it on something in his tank quite awhile ago, but it's been healed by now. I will see if I can get a good picture.

edit- here's a picture, sorry its low quality.

 

[Lyssa]

No one? :/

 

[LSuzuki]

I can see why you are concerned - I'd be worried if it were mine too. What I'd be worried about is some sort of systemic infection, but if it is only on the very tip of the tail, probably not. I'm hoping the experts say that it isn't something serious.

Perhaps it is associated with the previous injury and is still regrowing. Is there any chance it is getting rubbed against something or dragged between something, like a thin gap that the tail slips into as the axolotl climbs over?

I'm definitely not an expert, but I'll ask the questions the experts usually ask ... What are the water parameters? Are ammonia and nitrite both 0 and nitrate acceptably low? What is the water temperature?