Is this ick?

[Mariac1990]

I just noticed these white spots on my fish. None of the others have it, just him. It isn’t spots it’s streaks on his dorsal fin. What could it be?

 

[MuddyWaters]

Hard for me to tell in that picture. Maybe one of the other folks can see it.

 

[fishorama]

It doesn't look like ich to me. Ich can look different on plecos' bodies but not usually their fins, just the usual salt-like dots. Could it be a scrape from a cave or rock it hangs around? Until you hear from others, I'd go with large frequent water changes. That's my "when in doubt" 1st action, clean water can work miracles...it doesn't cure for ich, bacterial or fungal infections but can help reduce them until you know what to try.

 

[jaylach]

Not sure what it is but not Ich in my opinion. I suspect mucus from a minor injury.