Fungus or injury?

[Slinkee]

I found one of our axies with this spot on his tail this morning. He's also got what looks like maybe a crimp at the end? There were two small guppies in his tank and I saw one picking at it. The guppies have been removed but (and I hope the pictures come through) can anyone identify whether this is an infection or an injury? He's otherwise alone in a filtered ten gallon tank and still eating very well.

 

[melfly]

Doesn't quite look like fungus to me.

Hope someone else may be able to advise.

Could be a bit of an infection made worse by the fish.

Mel