Black spot on Guppy??

[Kerryn Blackwood]

Hi,
I've noticed in the past few days that my male guppy has developed a dark black spot on its side, it's not grown or shown any signs of it disappearing. I'm not sure as to what it is or if it's harmful, has anyone got any ideas?

Thanks in advance

 

[LyraGuppi]

Is it raised, or fuzzy looking?

 

[betta fish]

Could be normal pigmentation from what I can see, this is most likely a young guppy just getting his colours, he will most likely get more or they will get larger and on the other side too, nothing to worry about if this is the case

 

[Kerryn Blackwood]

It's not raised or fuzzy but it seems that the guppy has developed fin rot. He's lying at the bottom of the tank and is struggling for breath, his tail is also ragged looking. All the other fish in the tank are perfect so I'm thinking he's maybe been getting bullied by the other fish.

What should I do?

Thanks

 

[Demeter32]

Quarantine him and do water changes

 

[Soccerfreak]

How big of a tank so you have?