PlanetCatfish.com

i was wondering if it was possible for the pleco to have done this or maybe a pearl or dwarf guarami

Either pleco or gourami may nip fins if they are that way inclined. It's usually nothing to worry about, but if it's persistent, the fin may not heal properly.

If it's persistant, I suggest you remove one potential nipper at a time to see who is the guilty party (if you haven't got a second tank, you an perhaps keep the fish for a few days in a breeder net).

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Mats

It isn't clear to me what fish's fin was ripped, a Cory? The plecos do this when exercizing their territorial imperative. Gouramis would not be high on my list of suspects.