Does anyone know what's wrong with his tail?

[DoMforce182]

He's had this for a while, he eats, swims and everything just fine. I'm not sure what is wrong with his tail, the clear part is going further and further on his tail. What do I do to get rid of this? Any help would be appreciated. Thanks!

 

[xxianxx]

It just looks like a tail regenerating to me, keep an eye on it, if it goes fluffy it is fungus. Nice bit of green on that axy, could you put a full pic up?

 

[NeekaLovesYou]

As said, just looks like tissue growing to me. I've found it's more common in juveniles but it's nothing to worry about.