Help! What is on my clown fish?

[Forrest Dunavant]

One of my clownfish died, and the other one looks sick as well. It's a relatively new tank. Kinda looks like he's caught whatever killed the other clown. Please help me identify what's likely wrong? Guessing it's some type of disease but am too new to saltwater aquariums to know what it could be.

 

[nano_ryan]

Some bacterial disease probably. I would make a qt with DT rocks or substrate, and mix in some melafix. I hope your little guy makes it

 

[Rickybobby]

Looks like brook. Do some searches on it