Red spot on Axie's tail

[Canis]

My albino axolotl seems to have developed a few red spots in a spot on his tail. I'm very new to keeping axolotls, so I'm not sure if this is anything normal or something to be worried about. Anyone know what might be causing it?

 

[Elise]

It looks like a small abrasion or bruise and is fairly common. I don't believe injuries like this can even be avoided, as I've had mine incur something similar in glass container once.