I am guessing its an injury, but that day we did put some wild fish into the tank for feeders. The reason I'm guessing its an injury is because a few little kids came to our house for a party, they are co workers of my family. They were being idiots and kept poking and slapping my fish tank, my poor Jardini was flying around and got really scared. I was really, really pissed and wanted to kick them out. They are definitely not coming to my place again, they hurt my fish. But is there another reason you can think of?