I just bought a blue tang and he looked fine the first day. I came down this morning and his left side, around his brain, was all lumpy nad yellow. It wasnt the whole left side, just around the top of his head. Is this a disease or stress???
Both.
It can be early hole in the head "disease" or lateral line "disease" which is more visible in stressful periods and also brought on by stress (and poor diet). As it progresses (due to prolonged stress or poor diet) it is more and more visible and eventually never goes away.
Be calm around him, make sure he has lots of hidey spots, feed lots of seaweed and spirulina, and keep his water quality high. Als make sure he is in a large tank of proper heat and water flow.
He probably just hit it i wud leave the lites off thou so it doesnt stress him out since its on his head
