Ottos can suck on slime coating, however I often see mine 'chase' other fish but they've not done any harm. I dont think its anything to worry about
Just keep an eye on it, if one of the danios gets an infection on its side around where the otto attached itself, only then should you start worrying
--Edit--
Time for a rant about CAE
(Some will recognise this from one of my earlier posts
I know this is fighting a fight that cant be won by the side I'm on because there's so much bad about them already, but hey =)
I honestly do not believe they're as bad as people say they are. Personally I have 6 of them, only 1 of them has turned 'bad' the other 5 havent. Also, they DO eat algae when they're young, I've never had any algae problems and when it started to come up they'd get rid of it. When getting older, they still eat algae but just less. Mine Love cucumber =) Also those that do attack other fish are known to (just like all (repeat the All again) other suckermouths can do) attack flat boddied fish.
I'm not saying you should keep him, seeing as there is a risk. All I'm trying to say is that they're really not all that bad, and there Are people around who have positive experiences with them as well. And please do not forgot its not only the chinese algae eater that can start feeding on slime coating, its all suckermouths, its just a risk you take, that with CAEs is a bit bigger
End Rant! tongue2.gif Once again, not trying to cause arguements here, not making a fight of it, just giving my opinion =)
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