help identifying if something is wrong with sailfin

[chris041177]

Hello, my sailfin has a large white bump on his fin. He shows no signs of illness that I can tell, he's very active, eats nori, and picks at rocks. It's been about 3 days since I noticed it, no new spots have appeared and no other fish have any so I don't think it's ich. What does it look like to you? Did he just scuff it up or is it something else?

 

[snorvich]

How long have you had the fish? When was the last fish introduced into the tank? Picture is not definitive.

 

[chris041177]

He was bought\introduced 3-4 weeks ago. Sorry about the pics he is constantly swimming. He had it out with my yellow tang at first so I think it may just be a wound from fighting. They are buds now though. It looks kind of like something stuck to his fin not like a hole or spot.

 

[snorvich]

Google lymphocystis. Just FYI, fish are never "best buds" especially if they occupy the same ecological niche.

 

[chris041177]

Thanks, I'll check it out. I know they're not really friends, just saying they no longer fight and they swim together. ..