Hey dudees

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Like i think i've mentioned in a post before (but i can't find it, which is why i'm starting a new thread), my tetras have chunks missing out of their fins, but i can never catch the culprit! Its not fin rot, because i've researched that, and it looks nothing like that. I've researched "fin nipping" and it looks like this is the case...
HOWEVER! No matter how hard i try, i can't find the fish thats biting all the others, but i think i have a clue.

...
One of the glowlights is spotless. Its fins are completely normal, and its just perfect! Whilst most, if not all of the others have chunks of their fins missing...
So, is it likely that this glowlight is the little nipper?