Gourami seems sick with strange behavior

[Smoothguitar]

Hi friends,
We added 3 gouramis to this tank, 2 are doing fine but this one is not. It has something on its upper dorsal fin, looks like a white growth. It is also behaving very strange, it does a very quick forward and backward motion, repeatedly. I don’t believe it will make it much longer.
This is an established tank with tetras and shrimp.
Does anyone have any clues? I have a picture

 

[SomeoneFISHy]

I am not an expert on disease, but it could be Ich. I'd recommend placing it in a quarantine tank, to both prevent spread to other creatures, and to isolate the gourami.