Rift lake cichlid with red spots

[AmyKieran]

This is my pseudotropheus trewassae and it seems to have gathered these red dots along on a part on its back. Any ideas?

Ammonia - 0
Nitrite - 0
Nitrate - 20 (water change day)

Only change recently has been changing decor from artificial to real plants

 

[Wills]

They look like bites to me

 

[AmyKieran]

They look like bites to me

Possibly, the fish is not showing any other signs of distress

Il keep an eye on it

 

[Colin_T]

doesn't look like a disease

might have scratched itself on the rocks

monitor and see how it goes