Hello, I’ve had theses two gold head sleeper gobies for a couple months now. Today ive just noticed a red patch on one of them it’s only on the one side of the goby quite hard to get a picture of it as he keeps trying to hide!
I’d love some help identifying and how to treat this please. they have a deep cave under a rock the second one appears to have no discolouration. Seems to be breathing a little quick but still eating frozen (they have both always loved eating frozen food)

I’d love some help identifying and how to treat this please. they have a deep cave under a rock the second one appears to have no discolouration. Seems to be breathing a little quick but still eating frozen (they have both always loved eating frozen food)

